Update external calendar modal help to include Google Calendar

Added Google Calendar setup instructions alongside existing Outlook 365 instructions.
Updated modal title to "Setting up External Calendars" and reorganized help text
to show both supported platforms with specific step-by-step instructions.

Google Calendar: hover over calendar → three dots → Settings and sharing →
Integrate calendar → Public address in iCal format

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

backend/Cargo.toml

@@ -22,6 +22,7 @@ hyper = { version = "1.0", features = ["full"] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 chrono = { version = "0.4", features = ["serde"] }
+chrono-tz = "0.8"
 uuid = { version = "1.0", features = ["v4", "serde"] }
 anyhow = "1.0"
 

backend/migrations/006_create_external_calendars_table.sql

@@ -0,0 +1,16 @@
+-- Create external_calendars table
+CREATE TABLE external_calendars (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    user_id INTEGER NOT NULL,
+    name TEXT NOT NULL,
+    url TEXT NOT NULL,
+    color TEXT NOT NULL DEFAULT '#4285f4',
+    is_visible BOOLEAN NOT NULL DEFAULT 1,
+    created_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+    updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
+    last_fetched DATETIME,
+    FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
+);
+
+-- Create index for performance
+CREATE INDEX idx_external_calendars_user_id ON external_calendars(user_id);

backend/migrations/007_create_external_calendar_cache_table.sql

@@ -0,0 +1,14 @@
+-- Create external calendar cache table for storing ICS data
+CREATE TABLE external_calendar_cache (
+    id INTEGER PRIMARY KEY AUTOINCREMENT,
+    external_calendar_id INTEGER NOT NULL,
+    ics_data TEXT NOT NULL,
+    cached_at DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    etag TEXT,
+    FOREIGN KEY (external_calendar_id) REFERENCES external_calendars(id) ON DELETE CASCADE,
+    UNIQUE(external_calendar_id)
+);
+
+-- Index for faster lookups
+CREATE INDEX idx_external_calendar_cache_calendar_id ON external_calendar_cache(external_calendar_id);
+CREATE INDEX idx_external_calendar_cache_cached_at ON external_calendar_cache(cached_at);

backend/src/auth.rs

@@ -112,6 +112,17 @@ impl AuthService {
         self.decode_token(token)
     }
 
+    /// Get user from token
+    pub async fn get_user_from_token(&self, token: &str) -> Result<crate::db::User, ApiError> {
+        let claims = self.verify_token(token)?;
+        
+        let user_repo = UserRepository::new(&self.db);
+        user_repo
+            .find_or_create(&claims.username, &claims.server_url)
+            .await
+            .map_err(|e| ApiError::Database(format!("Failed to get user: {}", e)))
+    }
+
     /// Create CalDAV config from token
     pub fn caldav_config_from_token(
         &self,

backend/src/db.rs

@@ -1,4 +1,4 @@
-use chrono::{DateTime, Utc};
+use chrono::{DateTime, Duration, Utc};
 use serde::{Deserialize, Serialize};
 use sqlx::sqlite::{SqlitePool, SqlitePoolOptions};
 use sqlx::{FromRow, Result};
@@ -99,6 +99,38 @@ pub struct UserPreferences {
     pub updated_at: DateTime<Utc>,
 }
 
+/// External calendar model
+#[derive(Debug, Clone, Serialize, Deserialize, FromRow)]
+pub struct ExternalCalendar {
+    pub id: i32,
+    pub user_id: String,
+    pub name: String,
+    pub url: String,
+    pub color: String,
+    pub is_visible: bool,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+    pub last_fetched: Option<DateTime<Utc>>,
+}
+
+impl ExternalCalendar {
+    /// Create a new external calendar
+    pub fn new(user_id: String, name: String, url: String, color: String) -> Self {
+        let now = Utc::now();
+        Self {
+            id: 0, // Will be set by database
+            user_id,
+            name,
+            url,
+            color,
+            is_visible: true,
+            created_at: now,
+            updated_at: now,
+            last_fetched: None,
+        }
+    }
+}
+
 impl UserPreferences {
     /// Create default preferences for a new user
     pub fn default_for_user(user_id: String) -> Self {
@@ -311,3 +343,146 @@ impl<'a> PreferencesRepository<'a> {
         Ok(())
     }
 }
+
+/// Repository for ExternalCalendar operations
+pub struct ExternalCalendarRepository<'a> {
+    db: &'a Database,
+}
+
+impl<'a> ExternalCalendarRepository<'a> {
+    pub fn new(db: &'a Database) -> Self {
+        Self { db }
+    }
+
+    /// Get all external calendars for a user
+    pub async fn get_by_user(&self, user_id: &str) -> Result<Vec<ExternalCalendar>> {
+        sqlx::query_as::<_, ExternalCalendar>(
+            "SELECT * FROM external_calendars WHERE user_id = ? ORDER BY created_at ASC",
+        )
+        .bind(user_id)
+        .fetch_all(self.db.pool())
+        .await
+    }
+
+    /// Create a new external calendar
+    pub async fn create(&self, calendar: &ExternalCalendar) -> Result<i32> {
+        let result = sqlx::query(
+            "INSERT INTO external_calendars (user_id, name, url, color, is_visible, created_at, updated_at) 
+             VALUES (?, ?, ?, ?, ?, ?, ?)",
+        )
+        .bind(&calendar.user_id)
+        .bind(&calendar.name)
+        .bind(&calendar.url)
+        .bind(&calendar.color)
+        .bind(&calendar.is_visible)
+        .bind(&calendar.created_at)
+        .bind(&calendar.updated_at)
+        .execute(self.db.pool())
+        .await?;
+
+        Ok(result.last_insert_rowid() as i32)
+    }
+
+    /// Update an external calendar
+    pub async fn update(&self, id: i32, calendar: &ExternalCalendar) -> Result<()> {
+        sqlx::query(
+            "UPDATE external_calendars 
+             SET name = ?, url = ?, color = ?, is_visible = ?, updated_at = ?
+             WHERE id = ? AND user_id = ?",
+        )
+        .bind(&calendar.name)
+        .bind(&calendar.url)
+        .bind(&calendar.color)
+        .bind(&calendar.is_visible)
+        .bind(Utc::now())
+        .bind(id)
+        .bind(&calendar.user_id)
+        .execute(self.db.pool())
+        .await?;
+
+        Ok(())
+    }
+
+    /// Delete an external calendar
+    pub async fn delete(&self, id: i32, user_id: &str) -> Result<()> {
+        sqlx::query("DELETE FROM external_calendars WHERE id = ? AND user_id = ?")
+            .bind(id)
+            .bind(user_id)
+            .execute(self.db.pool())
+            .await?;
+
+        Ok(())
+    }
+
+    /// Update last_fetched timestamp
+    pub async fn update_last_fetched(&self, id: i32, user_id: &str) -> Result<()> {
+        sqlx::query(
+            "UPDATE external_calendars SET last_fetched = ? WHERE id = ? AND user_id = ?",
+        )
+        .bind(Utc::now())
+        .bind(id)
+        .bind(user_id)
+        .execute(self.db.pool())
+        .await?;
+
+        Ok(())
+    }
+
+    /// Get cached ICS data for an external calendar
+    pub async fn get_cached_data(&self, external_calendar_id: i32) -> Result<Option<(String, DateTime<Utc>)>> {
+        let result = sqlx::query_as::<_, (String, DateTime<Utc>)>(
+            "SELECT ics_data, cached_at FROM external_calendar_cache WHERE external_calendar_id = ?",
+        )
+        .bind(external_calendar_id)
+        .fetch_optional(self.db.pool())
+        .await?;
+
+        Ok(result)
+    }
+
+    /// Update cache with new ICS data
+    pub async fn update_cache(&self, external_calendar_id: i32, ics_data: &str, etag: Option<&str>) -> Result<()> {
+        sqlx::query(
+            "INSERT INTO external_calendar_cache (external_calendar_id, ics_data, etag, cached_at)
+             VALUES (?, ?, ?, ?)
+             ON CONFLICT(external_calendar_id) DO UPDATE SET
+             ics_data = excluded.ics_data,
+             etag = excluded.etag,
+             cached_at = excluded.cached_at",
+        )
+        .bind(external_calendar_id)
+        .bind(ics_data)
+        .bind(etag)
+        .bind(Utc::now())
+        .execute(self.db.pool())
+        .await?;
+
+        Ok(())
+    }
+
+    /// Check if cache is stale (older than max_age_minutes)
+    pub async fn is_cache_stale(&self, external_calendar_id: i32, max_age_minutes: i64) -> Result<bool> {
+        let cutoff_time = Utc::now() - Duration::minutes(max_age_minutes);
+        
+        let result = sqlx::query_scalar::<_, i64>(
+            "SELECT COUNT(*) FROM external_calendar_cache 
+             WHERE external_calendar_id = ? AND cached_at > ?",
+        )
+        .bind(external_calendar_id)
+        .bind(cutoff_time)
+        .fetch_one(self.db.pool())
+        .await?;
+
+        Ok(result == 0)
+    }
+
+    /// Clear cache for an external calendar
+    pub async fn clear_cache(&self, external_calendar_id: i32) -> Result<()> {
+        sqlx::query("DELETE FROM external_calendar_cache WHERE external_calendar_id = ?")
+            .bind(external_calendar_id)
+            .execute(self.db.pool())
+            .await?;
+
+        Ok(())
+    }
+}

backend/src/handlers.rs

@@ -1,12 +0,0 @@
-// Re-export all handlers from the modular structure
-mod auth;
-mod calendar;
-mod events;
-mod preferences;
-mod series;
-
-pub use auth::{get_user_info, login, verify_token};
-pub use calendar::{create_calendar, delete_calendar};
-pub use events::{create_event, delete_event, get_calendar_events, refresh_event, update_event};
-pub use preferences::{get_preferences, logout, update_preferences};
-pub use series::{create_event_series, delete_event_series, update_event_series};

backend/src/handlers/auth.rs

@@ -93,6 +93,7 @@ pub async fn get_user_info(
             path: path.clone(),
             display_name: extract_calendar_name(path),
             color: generate_calendar_color(path),
+            is_visible: true, // Default to visible
         })
         .collect();
 

backend/src/handlers/events.rs

@@ -852,10 +852,11 @@ fn parse_event_datetime(
         .map_err(|_| format!("Invalid date format: {}. Expected YYYY-MM-DD", date_str))?;
 
     if all_day {
-        // For all-day events, use midnight UTC
+        // For all-day events, use noon UTC to avoid timezone boundary issues
+        // This ensures the date remains correct when converted to any local timezone
         let datetime = date
-            .and_hms_opt(0, 0, 0)
+            .and_hms_opt(12, 0, 0)
-            .ok_or_else(|| "Failed to create midnight datetime".to_string())?;
+            .ok_or_else(|| "Failed to create noon datetime".to_string())?;
         Ok(Utc.from_utc_datetime(&datetime))
     } else {
         // Parse the time

backend/src/handlers/external_calendars.rs

@@ -0,0 +1,142 @@
+use axum::{
+    extract::{Path, State},
+    response::Json,
+};
+use serde::{Deserialize, Serialize};
+use std::sync::Arc;
+
+use crate::{
+    db::{ExternalCalendar, ExternalCalendarRepository},
+    models::ApiError,
+    AppState,
+};
+
+use super::auth::{extract_bearer_token};
+
+#[derive(Debug, Deserialize)]
+pub struct CreateExternalCalendarRequest {
+    pub name: String,
+    pub url: String,
+    pub color: String,
+}
+
+#[derive(Debug, Deserialize)]
+pub struct UpdateExternalCalendarRequest {
+    pub name: String,
+    pub url: String,
+    pub color: String,
+    pub is_visible: bool,
+}
+
+#[derive(Debug, Serialize)]
+pub struct ExternalCalendarResponse {
+    pub id: i32,
+    pub name: String,
+    pub url: String,
+    pub color: String,
+    pub is_visible: bool,
+    pub created_at: chrono::DateTime<chrono::Utc>,
+    pub updated_at: chrono::DateTime<chrono::Utc>,
+    pub last_fetched: Option<chrono::DateTime<chrono::Utc>>,
+}
+
+impl From<ExternalCalendar> for ExternalCalendarResponse {
+    fn from(calendar: ExternalCalendar) -> Self {
+        Self {
+            id: calendar.id,
+            name: calendar.name,
+            url: calendar.url,
+            color: calendar.color,
+            is_visible: calendar.is_visible,
+            created_at: calendar.created_at,
+            updated_at: calendar.updated_at,
+            last_fetched: calendar.last_fetched,
+        }
+    }
+}
+
+pub async fn get_external_calendars(
+    headers: axum::http::HeaderMap,
+    State(app_state): State<Arc<AppState>>,
+) -> Result<Json<Vec<ExternalCalendarResponse>>, ApiError> {
+    // Extract and verify token, get user
+    let token = extract_bearer_token(&headers)?;
+    let user = app_state.auth_service.get_user_from_token(&token).await?;
+
+    let repo = ExternalCalendarRepository::new(&app_state.db);
+    let calendars = repo
+        .get_by_user(&user.id)
+        .await
+        .map_err(|e| ApiError::Database(format!("Failed to get external calendars: {}", e)))?;
+
+    let response: Vec<ExternalCalendarResponse> = calendars.into_iter().map(Into::into).collect();
+    Ok(Json(response))
+}
+
+pub async fn create_external_calendar(
+    headers: axum::http::HeaderMap,
+    State(app_state): State<Arc<AppState>>,
+    Json(request): Json<CreateExternalCalendarRequest>,
+) -> Result<Json<ExternalCalendarResponse>, ApiError> {
+    let token = extract_bearer_token(&headers)?;
+    let user = app_state.auth_service.get_user_from_token(&token).await?;
+
+    let calendar = ExternalCalendar::new(
+        user.id,
+        request.name,
+        request.url,
+        request.color,
+    );
+
+    let repo = ExternalCalendarRepository::new(&app_state.db);
+    let id = repo
+        .create(&calendar)
+        .await
+        .map_err(|e| ApiError::Database(format!("Failed to create external calendar: {}", e)))?;
+
+    let mut created_calendar = calendar;
+    created_calendar.id = id;
+
+    Ok(Json(created_calendar.into()))
+}
+
+pub async fn update_external_calendar(
+    headers: axum::http::HeaderMap,
+    State(app_state): State<Arc<AppState>>,
+    Path(id): Path<i32>,
+    Json(request): Json<UpdateExternalCalendarRequest>,
+) -> Result<Json<()>, ApiError> {
+    let token = extract_bearer_token(&headers)?;
+    let user = app_state.auth_service.get_user_from_token(&token).await?;
+
+    let mut calendar = ExternalCalendar::new(
+        user.id,
+        request.name,
+        request.url,
+        request.color,
+    );
+    calendar.is_visible = request.is_visible;
+
+    let repo = ExternalCalendarRepository::new(&app_state.db);
+    repo.update(id, &calendar)
+        .await
+        .map_err(|e| ApiError::Database(format!("Failed to update external calendar: {}", e)))?;
+
+    Ok(Json(()))
+}
+
+pub async fn delete_external_calendar(
+    headers: axum::http::HeaderMap,
+    State(app_state): State<Arc<AppState>>,
+    Path(id): Path<i32>,
+) -> Result<Json<()>, ApiError> {
+    let token = extract_bearer_token(&headers)?;
+    let user = app_state.auth_service.get_user_from_token(&token).await?;
+
+    let repo = ExternalCalendarRepository::new(&app_state.db);
+    repo.delete(id, &user.id)
+        .await
+        .map_err(|e| ApiError::Database(format!("Failed to delete external calendar: {}", e)))?;
+
+    Ok(Json(()))
+}

backend/src/handlers/ics_fetcher.rs

@@ -0,0 +1,410 @@
+use axum::{
+    extract::{Path, State},
+    response::Json,
+};
+use chrono::{DateTime, Utc};
+use ical::parser::ical::component::IcalEvent;
+use reqwest::Client;
+use serde::Serialize;
+use std::sync::Arc;
+
+use crate::{
+    db::ExternalCalendarRepository,
+    models::ApiError,
+    AppState,
+};
+
+// Import VEvent from calendar-models shared crate
+use calendar_models::VEvent;
+
+use super::auth::{extract_bearer_token};
+
+#[derive(Debug, Serialize)]
+pub struct ExternalCalendarEventsResponse {
+    pub events: Vec<VEvent>,
+    pub last_fetched: DateTime<Utc>,
+}
+
+pub async fn fetch_external_calendar_events(
+    headers: axum::http::HeaderMap,
+    State(app_state): State<Arc<AppState>>,
+    Path(id): Path<i32>,
+) -> Result<Json<ExternalCalendarEventsResponse>, ApiError> {
+    let token = extract_bearer_token(&headers)?;
+    let user = app_state.auth_service.get_user_from_token(&token).await?;
+
+    let repo = ExternalCalendarRepository::new(&app_state.db);
+    
+    // Get user's external calendars to verify ownership and get URL
+    let calendars = repo
+        .get_by_user(&user.id)
+        .await
+        .map_err(|e| ApiError::Database(format!("Failed to get external calendars: {}", e)))?;
+
+    let calendar = calendars
+        .into_iter()
+        .find(|c| c.id == id)
+        .ok_or_else(|| ApiError::NotFound("External calendar not found".to_string()))?;
+
+    if !calendar.is_visible {
+        return Ok(Json(ExternalCalendarEventsResponse {
+            events: vec![],
+            last_fetched: Utc::now(),
+        }));
+    }
+
+    // Check cache first
+    let cache_max_age_minutes = 5;
+    let mut ics_content = String::new();
+    let mut last_fetched = Utc::now();
+    let mut fetched_from_cache = false;
+
+    // Try to get from cache if not stale
+    match repo.is_cache_stale(id, cache_max_age_minutes).await {
+        Ok(is_stale) => {
+            if !is_stale {
+                // Cache is fresh, use it
+                if let Ok(Some((cached_data, cached_at))) = repo.get_cached_data(id).await {
+                    ics_content = cached_data;
+                    last_fetched = cached_at;
+                    fetched_from_cache = true;
+                }
+            }
+        }
+        Err(_) => {
+            // If cache check fails, proceed to fetch from URL
+        }
+    }
+
+    // If not fetched from cache, get from external URL
+    if !fetched_from_cache {
+        let client = Client::new();
+        let response = client
+            .get(&calendar.url)
+            .send()
+            .await
+            .map_err(|e| ApiError::Internal(format!("Failed to fetch calendar: {}", e)))?;
+
+        if !response.status().is_success() {
+            return Err(ApiError::Internal(format!("Calendar server returned: {}", response.status())));
+        }
+
+        ics_content = response
+            .text()
+            .await
+            .map_err(|e| ApiError::Internal(format!("Failed to read calendar content: {}", e)))?;
+
+        // Store in cache for future requests
+        let etag = None; // TODO: Extract ETag from response headers if available
+        if let Err(_) = repo.update_cache(id, &ics_content, etag).await {
+            // Log error but don't fail the request
+        }
+
+        // Update last_fetched timestamp
+        if let Err(_) = repo.update_last_fetched(id, &user.id).await {
+        }
+        
+        last_fetched = Utc::now();
+    }
+
+    // Parse ICS content
+    let events = parse_ics_content(&ics_content)
+        .map_err(|e| ApiError::BadRequest(format!("Failed to parse calendar: {}", e)))?;
+
+    Ok(Json(ExternalCalendarEventsResponse {
+        events,
+        last_fetched,
+    }))
+}
+
+fn parse_ics_content(ics_content: &str) -> Result<Vec<VEvent>, Box<dyn std::error::Error>> {
+    let reader = ical::IcalParser::new(ics_content.as_bytes());
+    let mut events = Vec::new();
+    let mut _total_components = 0;
+    let mut _failed_conversions = 0;
+
+    for calendar in reader {
+        let calendar = calendar?;
+        for component in calendar.events {
+            _total_components += 1;
+            match convert_ical_to_vevent(component) {
+                Ok(vevent) => {
+                    events.push(vevent);
+                }
+                Err(_) => {
+                    _failed_conversions += 1;
+                }
+            }
+        }
+    }
+
+
+    Ok(events)
+}
+
+fn convert_ical_to_vevent(ical_event: IcalEvent) -> Result<VEvent, Box<dyn std::error::Error>> {
+    use uuid::Uuid;
+
+    let mut summary = None;
+    let mut description = None;
+    let mut location = None;
+    let mut dtstart = None;
+    let mut dtend = None;
+    let mut uid = None;
+    let mut all_day = false;
+    let mut rrule = None;
+
+
+    // Extract properties
+    for property in ical_event.properties {
+        match property.name.as_str() {
+            "SUMMARY" => {
+                summary = property.value;
+            }
+            "DESCRIPTION" => {
+                description = property.value;
+            }
+            "LOCATION" => {
+                location = property.value;
+            }
+            "DTSTART" => {
+                if let Some(value) = property.value {
+                    // Check if it's a date-only value (all-day event)
+                    if value.len() == 8 && !value.contains('T') {
+                        all_day = true;
+                        // Parse YYYYMMDD format
+                        if let Ok(date) = chrono::NaiveDate::parse_from_str(&value, "%Y%m%d") {
+                            dtstart = Some(chrono::TimeZone::from_utc_datetime(&Utc, &date.and_hms_opt(12, 0, 0).unwrap()));
+                        }
+                    } else {
+                        // Extract timezone info from parameters
+                        let tzid = property.params.as_ref()
+                            .and_then(|params| params.iter().find(|(k, _)| k == "TZID"))
+                            .and_then(|(_, v)| v.first().cloned());
+                        
+                        // Parse datetime with timezone information
+                        if let Some(dt) = parse_datetime_with_tz(&value, tzid.as_deref()) {
+                            dtstart = Some(dt);
+                        }
+                    }
+                }
+            }
+            "DTEND" => {
+                if let Some(value) = property.value {
+                    if all_day && value.len() == 8 && !value.contains('T') {
+                        // For all-day events, DTEND is exclusive so use the date as-is at noon
+                        if let Ok(date) = chrono::NaiveDate::parse_from_str(&value, "%Y%m%d") {
+                            dtend = Some(chrono::TimeZone::from_utc_datetime(&Utc, &date.and_hms_opt(12, 0, 0).unwrap()));
+                        }
+                    } else {
+                        // Extract timezone info from parameters
+                        let tzid = property.params.as_ref()
+                            .and_then(|params| params.iter().find(|(k, _)| k == "TZID"))
+                            .and_then(|(_, v)| v.first().cloned());
+                        
+                        // Parse datetime with timezone information
+                        if let Some(dt) = parse_datetime_with_tz(&value, tzid.as_deref()) {
+                            dtend = Some(dt);
+                        }
+                    }
+                }
+            }
+            "UID" => {
+                uid = property.value;
+            }
+            "RRULE" => {
+                rrule = property.value;
+            }
+            _ => {} // Ignore other properties for now
+        }
+    }
+
+
+    let dtstart = dtstart.ok_or("Missing DTSTART")?;
+
+    let vevent = VEvent {
+        uid: uid.unwrap_or_else(|| Uuid::new_v4().to_string()),
+        dtstart,
+        dtend,
+        summary,
+        description,
+        location,
+        all_day,
+        rrule,
+        exdate: Vec::new(), // External calendars don't need exception handling
+        recurrence_id: None,
+        created: None,
+        last_modified: None,
+        dtstamp: Utc::now(),
+        sequence: Some(0),
+        status: None,
+        transp: None,
+        organizer: None,
+        attendees: Vec::new(),
+        url: None,
+        attachments: Vec::new(),
+        categories: Vec::new(),
+        priority: None,
+        resources: Vec::new(),
+        related_to: None,
+        geo: None,
+        duration: None,
+        class: None,
+        contact: None,
+        comment: None,
+        rdate: Vec::new(),
+        alarms: Vec::new(),
+        etag: None,
+        href: None,
+        calendar_path: None,
+    };
+
+    Ok(vevent)
+}
+
+fn parse_datetime_with_tz(datetime_str: &str, tzid: Option<&str>) -> Option<DateTime<Utc>> {
+    use chrono::TimeZone;
+    use chrono_tz::Tz;
+    
+    
+    // Try various datetime formats commonly found in ICS files
+    
+    // Format: 20231201T103000Z (UTC) - handle as naive datetime first
+    if datetime_str.ends_with('Z') {
+        let datetime_without_z = &datetime_str[..datetime_str.len()-1];
+        if let Ok(naive_dt) = chrono::NaiveDateTime::parse_from_str(datetime_without_z, "%Y%m%dT%H%M%S") {
+            return Some(naive_dt.and_utc());
+        }
+    }
+
+    // Format: 20231201T103000-0500 (with timezone offset)
+    if let Ok(dt) = DateTime::parse_from_str(datetime_str, "%Y%m%dT%H%M%S%z") {
+        return Some(dt.with_timezone(&Utc));
+    }
+
+    // Format: 2023-12-01T10:30:00Z (ISO format)
+    if let Ok(dt) = DateTime::parse_from_str(datetime_str, "%Y-%m-%dT%H:%M:%SZ") {
+        return Some(dt.with_timezone(&Utc));
+    }
+
+    // Handle naive datetime with timezone parameter
+    let naive_dt = if let Ok(dt) = chrono::NaiveDateTime::parse_from_str(datetime_str, "%Y%m%dT%H%M%S") {
+        Some(dt)
+    } else if let Ok(dt) = chrono::NaiveDateTime::parse_from_str(datetime_str, "%Y-%m-%dT%H:%M:%S") {
+        Some(dt)
+    } else {
+        None
+    };
+
+    if let Some(naive_dt) = naive_dt {
+        // If TZID is provided, try to parse it
+        if let Some(tzid_str) = tzid {
+            // Handle common timezone formats
+            let tz_result = if tzid_str.starts_with("/mozilla.org/") {
+                // Mozilla/Thunderbird format: /mozilla.org/20070129_1/Europe/London
+                tzid_str.split('/').last().and_then(|tz_name| tz_name.parse::<Tz>().ok())
+            } else if tzid_str.contains('/') {
+                // Standard timezone format: America/New_York, Europe/London
+                tzid_str.parse::<Tz>().ok()
+            } else {
+                // Try common abbreviations and Windows timezone names
+                match tzid_str {
+                    // Standard abbreviations
+                    "EST" => Some(Tz::America__New_York),
+                    "PST" => Some(Tz::America__Los_Angeles),
+                    "MST" => Some(Tz::America__Denver), 
+                    "CST" => Some(Tz::America__Chicago),
+                    
+                    // North America - Windows timezone names to IANA mapping
+                    "Mountain Standard Time" => Some(Tz::America__Denver),
+                    "Eastern Standard Time" => Some(Tz::America__New_York),
+                    "Central Standard Time" => Some(Tz::America__Chicago),
+                    "Pacific Standard Time" => Some(Tz::America__Los_Angeles),
+                    "Mountain Daylight Time" => Some(Tz::America__Denver),
+                    "Eastern Daylight Time" => Some(Tz::America__New_York),
+                    "Central Daylight Time" => Some(Tz::America__Chicago),
+                    "Pacific Daylight Time" => Some(Tz::America__Los_Angeles),
+                    "Hawaiian Standard Time" => Some(Tz::Pacific__Honolulu),
+                    "Alaskan Standard Time" => Some(Tz::America__Anchorage),
+                    "Alaskan Daylight Time" => Some(Tz::America__Anchorage),
+                    "Atlantic Standard Time" => Some(Tz::America__Halifax),
+                    "Newfoundland Standard Time" => Some(Tz::America__St_Johns),
+                    
+                    // Europe
+                    "GMT Standard Time" => Some(Tz::Europe__London),
+                    "Greenwich Standard Time" => Some(Tz::UTC),
+                    "W. Europe Standard Time" => Some(Tz::Europe__Berlin),
+                    "Central Europe Standard Time" => Some(Tz::Europe__Warsaw),
+                    "Romance Standard Time" => Some(Tz::Europe__Paris),
+                    "Central European Standard Time" => Some(Tz::Europe__Belgrade),
+                    "E. Europe Standard Time" => Some(Tz::Europe__Bucharest),
+                    "FLE Standard Time" => Some(Tz::Europe__Helsinki),
+                    "GTB Standard Time" => Some(Tz::Europe__Athens),
+                    "Russian Standard Time" => Some(Tz::Europe__Moscow),
+                    "Turkey Standard Time" => Some(Tz::Europe__Istanbul),
+                    
+                    // Asia
+                    "China Standard Time" => Some(Tz::Asia__Shanghai),
+                    "Tokyo Standard Time" => Some(Tz::Asia__Tokyo),
+                    "Korea Standard Time" => Some(Tz::Asia__Seoul),
+                    "Singapore Standard Time" => Some(Tz::Asia__Singapore),
+                    "India Standard Time" => Some(Tz::Asia__Kolkata),
+                    "Pakistan Standard Time" => Some(Tz::Asia__Karachi),
+                    "Bangladesh Standard Time" => Some(Tz::Asia__Dhaka),
+                    "Thailand Standard Time" => Some(Tz::Asia__Bangkok),
+                    "SE Asia Standard Time" => Some(Tz::Asia__Bangkok),
+                    "Myanmar Standard Time" => Some(Tz::Asia__Yangon),
+                    "Sri Lanka Standard Time" => Some(Tz::Asia__Colombo),
+                    "Nepal Standard Time" => Some(Tz::Asia__Kathmandu),
+                    "Central Asia Standard Time" => Some(Tz::Asia__Almaty),
+                    "West Asia Standard Time" => Some(Tz::Asia__Tashkent),
+                    "Afghanistan Standard Time" => Some(Tz::Asia__Kabul),
+                    "Iran Standard Time" => Some(Tz::Asia__Tehran),
+                    "Arabian Standard Time" => Some(Tz::Asia__Dubai),
+                    "Arab Standard Time" => Some(Tz::Asia__Riyadh),
+                    "Israel Standard Time" => Some(Tz::Asia__Jerusalem),
+                    "Jordan Standard Time" => Some(Tz::Asia__Amman),
+                    "Syria Standard Time" => Some(Tz::Asia__Damascus),
+                    "Middle East Standard Time" => Some(Tz::Asia__Beirut),
+                    "Egypt Standard Time" => Some(Tz::Africa__Cairo),
+                    "South Africa Standard Time" => Some(Tz::Africa__Johannesburg),
+                    "E. Africa Standard Time" => Some(Tz::Africa__Nairobi),
+                    "W. Central Africa Standard Time" => Some(Tz::Africa__Lagos),
+                    
+                    // Asia Pacific
+                    "AUS Eastern Standard Time" => Some(Tz::Australia__Sydney),
+                    "AUS Central Standard Time" => Some(Tz::Australia__Darwin),
+                    "W. Australia Standard Time" => Some(Tz::Australia__Perth),
+                    "Tasmania Standard Time" => Some(Tz::Australia__Hobart),
+                    "New Zealand Standard Time" => Some(Tz::Pacific__Auckland),
+                    "Fiji Standard Time" => Some(Tz::Pacific__Fiji),
+                    "Tonga Standard Time" => Some(Tz::Pacific__Tongatapu),
+                    
+                    // South America
+                    "Argentina Standard Time" => Some(Tz::America__Buenos_Aires),
+                    "E. South America Standard Time" => Some(Tz::America__Sao_Paulo),
+                    "SA Eastern Standard Time" => Some(Tz::America__Cayenne),
+                    "SA Pacific Standard Time" => Some(Tz::America__Bogota),
+                    "SA Western Standard Time" => Some(Tz::America__La_Paz),
+                    "Pacific SA Standard Time" => Some(Tz::America__Santiago),
+                    "Venezuela Standard Time" => Some(Tz::America__Caracas),
+                    "Montevideo Standard Time" => Some(Tz::America__Montevideo),
+                    
+                    // Try parsing as IANA name
+                    _ => tzid_str.parse::<Tz>().ok()
+                }
+            };
+
+            if let Some(tz) = tz_result {
+                if let Some(dt_with_tz) = tz.from_local_datetime(&naive_dt).single() {
+                    return Some(dt_with_tz.with_timezone(&Utc));
+                }
+            }
+        }
+        
+        // If no timezone info or parsing failed, treat as UTC (safer than local time assumptions)
+        return Some(chrono::TimeZone::from_utc_datetime(&Utc, &naive_dt));
+    }
+
+    None
+}

backend/src/handlers/mod.rs

@@ -0,0 +1,15 @@
+pub mod auth;
+pub mod calendar;
+pub mod events;
+pub mod external_calendars;
+pub mod ics_fetcher;
+pub mod preferences;
+pub mod series;
+
+pub use auth::*;
+pub use calendar::*;
+pub use events::*;
+pub use external_calendars::*;
+pub use ics_fetcher::*;
+pub use preferences::*;
+pub use series::*;

backend/src/handlers/series.rs

@@ -262,8 +262,8 @@ pub async fn update_event_series(
     Json(request): Json<UpdateEventSeriesRequest>,
 ) -> Result<Json<UpdateEventSeriesResponse>, ApiError> {
     println!(
-        "🔄 Update event series request received: series_uid='{}', update_scope='{}'",
+        "🔄 Update event series request received: series_uid='{}', update_scope='{}', recurrence_count={:?}, recurrence_end_date={:?}",
-        request.series_uid, request.update_scope
+        request.series_uid, request.update_scope, request.recurrence_count, request.recurrence_end_date
     );
 
     // Extract and verify token
@@ -397,8 +397,9 @@ pub async fn update_event_series(
     };
 
     let (start_datetime, end_datetime) = if request.all_day {
+        // For all-day events, use noon UTC to avoid timezone boundary issues
         let start_dt = start_date
-            .and_hms_opt(0, 0, 0)
+            .and_hms_opt(12, 0, 0)
             .ok_or_else(|| ApiError::BadRequest("Invalid start date".to_string()))?;
 
         // For all-day events, also preserve the original date pattern
@@ -414,20 +415,13 @@ pub async fn update_event_series(
         };
 
         let end_dt = end_date
-            .and_hms_opt(23, 59, 59)
+            .and_hms_opt(12, 0, 0)
             .ok_or_else(|| ApiError::BadRequest("Invalid end date".to_string()))?;
 
-        // Convert from local time to UTC
+        // For all-day events, use UTC directly (no local conversion needed)
-        let start_local = chrono::Local.from_local_datetime(&start_dt)
-            .single()
-            .ok_or_else(|| ApiError::BadRequest("Ambiguous start datetime".to_string()))?;
-        let end_local = chrono::Local.from_local_datetime(&end_dt)
-            .single()
-            .ok_or_else(|| ApiError::BadRequest("Ambiguous end datetime".to_string()))?;
-        
         (
-            start_local.with_timezone(&chrono::Utc),
+            chrono::Utc.from_utc_datetime(&start_dt),
-            end_local.with_timezone(&chrono::Utc),
+            chrono::Utc.from_utc_datetime(&end_dt),
         )
     } else {
         let start_time = if !request.start_time.is_empty() {
@@ -765,9 +759,36 @@ fn update_entire_series(
     updated_event.last_modified = Some(now);
     // Keep original created timestamp to preserve event history
 
-    // For simple updates (like drag operations), preserve the existing RRULE
+    // Update RRULE if recurrence parameters are provided
-    // For more complex updates, we might need to regenerate it, but for now keep it simple
+    if let Some(ref existing_rrule) = updated_event.rrule {
-    // updated_event.rrule remains unchanged from the clone
+        let mut new_rrule = existing_rrule.clone();
+        println!("🔄 Original RRULE: {}", existing_rrule);
+        
+        // Update COUNT if provided
+        if let Some(count) = request.recurrence_count {
+            println!("🔄 Updating RRULE with new COUNT: {}", count);
+            // Remove old COUNT or UNTIL parameters
+            new_rrule = new_rrule.split(';')
+                .filter(|part| !part.starts_with("COUNT=") && !part.starts_with("UNTIL="))
+                .collect::<Vec<_>>()
+                .join(";");
+            // Add new COUNT
+            new_rrule = format!("{};COUNT={}", new_rrule, count);
+        } else if let Some(ref end_date) = request.recurrence_end_date {
+            println!("🔄 Updating RRULE with new UNTIL: {}", end_date);
+            // Remove old COUNT or UNTIL parameters
+            new_rrule = new_rrule.split(';')
+                .filter(|part| !part.starts_with("COUNT=") && !part.starts_with("UNTIL="))
+                .collect::<Vec<_>>()
+                .join(";");
+            // Add new UNTIL (convert YYYY-MM-DD to YYYYMMDD format)
+            let until_date = end_date.replace("-", "");
+            new_rrule = format!("{};UNTIL={}", new_rrule, until_date);
+        }
+        
+        println!("🔄 Updated RRULE: {}", new_rrule);
+        updated_event.rrule = Some(new_rrule);
+    }
 
     // Copy the updated event back to existing_event for the main handler
     *existing_event = updated_event.clone();

backend/src/lib.rs

@@ -1,6 +1,6 @@
 use axum::{
     response::Json,
-    routing::{get, post},
+    routing::{delete, get, post},
     Router,
 };
 use std::sync::Arc;
@@ -72,6 +72,12 @@ pub async fn run_server() -> Result<(), Box<dyn std::error::Error>> {
         .route("/api/preferences", get(handlers::get_preferences))
         .route("/api/preferences", post(handlers::update_preferences))
         .route("/api/auth/logout", post(handlers::logout))
+        // External calendars endpoints
+        .route("/api/external-calendars", get(handlers::get_external_calendars))
+        .route("/api/external-calendars", post(handlers::create_external_calendar))
+        .route("/api/external-calendars/:id", post(handlers::update_external_calendar))
+        .route("/api/external-calendars/:id", delete(handlers::delete_external_calendar))
+        .route("/api/external-calendars/:id/events", get(handlers::fetch_external_calendar_events))
         .layer(
             CorsLayer::new()
                 .allow_origin(Any)

backend/src/models.rs

@@ -56,6 +56,7 @@ pub struct CalendarInfo {
     pub path: String,
     pub display_name: String,
     pub color: String,
+    pub is_visible: bool,
 }
 
 #[derive(Debug, Deserialize)]

frontend/Cargo.toml

@@ -37,6 +37,7 @@ reqwest = { version = "0.11", features = ["json"] }
 ical = "0.7"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
+serde-wasm-bindgen = "0.6"
 
 # Date and time handling
 chrono = { version = "0.4", features = ["serde", "wasm-bindgen"] }

frontend/src/app.rs

@@ -1,12 +1,14 @@
 use crate::components::{
     CalendarContextMenu, ContextMenu, CreateCalendarModal, CreateEventModal, DeleteAction,
-    EditAction, EventContextMenu, EventCreationData, RouteHandler, Sidebar, Theme, ViewMode,
+    EditAction, EventContextMenu, EventCreationData, ExternalCalendarModal, RouteHandler, 
+    Sidebar, Theme, ViewMode,
 };
 use crate::components::sidebar::{Style};
 use crate::models::ical::VEvent;
-use crate::services::{calendar_service::UserInfo, CalendarService};
+use crate::services::{calendar_service::{UserInfo, ExternalCalendar}, CalendarService};
 use chrono::NaiveDate;
 use gloo_storage::{LocalStorage, Storage};
+use gloo_timers::callback::Interval;
 use wasm_bindgen::JsCast;
 use web_sys::MouseEvent;
 use yew::prelude::*;
@@ -74,6 +76,12 @@ pub fn App() -> Html {
     let _recurring_edit_event = use_state(|| -> Option<VEvent> { None });
     let _recurring_edit_data = use_state(|| -> Option<EventCreationData> { None });
     
+    // External calendar state
+    let external_calendars = use_state(|| -> Vec<ExternalCalendar> { Vec::new() });
+    let external_calendar_events = use_state(|| -> Vec<VEvent> { Vec::new() });
+    let external_calendar_modal_open = use_state(|| false);
+    let refresh_interval = use_state(|| -> Option<Interval> { None });
+
     // Calendar view state - load from localStorage if available
     let current_view = use_state(|| {
         // Try to load saved view mode from localStorage
@@ -301,6 +309,80 @@ pub fn App() -> Html {
         });
     }
 
+    // Function to refresh external calendars
+    let refresh_external_calendars = {
+        let external_calendars = external_calendars.clone();
+        let external_calendar_events = external_calendar_events.clone();
+        Callback::from(move |_| {
+            let external_calendars = external_calendars.clone();
+            let external_calendar_events = external_calendar_events.clone();
+
+            wasm_bindgen_futures::spawn_local(async move {
+                // Load external calendars
+                match CalendarService::get_external_calendars().await {
+                    Ok(calendars) => {
+                        external_calendars.set(calendars.clone());
+                        
+                        // Load events for visible external calendars
+                        let mut all_events = Vec::new();
+                        for calendar in calendars {
+                            if calendar.is_visible {
+                                if let Ok(mut events) = CalendarService::fetch_external_calendar_events(calendar.id).await {
+                                    // Set calendar_path for color matching
+                                    for event in &mut events {
+                                        event.calendar_path = Some(format!("external_{}", calendar.id));
+                                    }
+                                    all_events.extend(events);
+                                }
+                            }
+                        }
+                        external_calendar_events.set(all_events);
+                    }
+                    Err(err) => {
+                        web_sys::console::log_1(
+                            &format!("Failed to load external calendars: {}", err).into(),
+                        );
+                    }
+                }
+            });
+        })
+    };
+
+    // Load external calendars when auth token is available and set up auto-refresh
+    {
+        let auth_token = auth_token.clone();
+        let refresh_external_calendars = refresh_external_calendars.clone();
+        let refresh_interval = refresh_interval.clone();
+        let external_calendars = external_calendars.clone();
+        let external_calendar_events = external_calendar_events.clone();
+
+        use_effect_with((*auth_token).clone(), move |token| {
+            if let Some(_) = token {
+                // Initial load
+                refresh_external_calendars.emit(());
+                
+                // Set up 5-minute refresh interval
+                let refresh_external_calendars = refresh_external_calendars.clone();
+                let interval = Interval::new(5 * 60 * 1000, move || {
+                    refresh_external_calendars.emit(());
+                });
+                refresh_interval.set(Some(interval));
+            } else {
+                // Clear data and interval when logged out
+                external_calendars.set(Vec::new());
+                external_calendar_events.set(Vec::new());
+                refresh_interval.set(None);
+            }
+
+            // Cleanup function
+            let refresh_interval = refresh_interval.clone();
+            move || {
+                // Clear interval on cleanup
+                refresh_interval.set(None);
+            }
+        });
+    }
+
     let on_outside_click = {
         let color_picker_open = color_picker_open.clone();
         let context_menu_open = context_menu_open.clone();
@@ -478,7 +560,10 @@ pub fn App() -> Html {
                                     params.13, // categories
                                     params.14, // reminder
                                     params.15, // recurrence
-                                    params.17, // calendar_path (skipping recurrence_days)
+                                    params.16, // recurrence_days
+                                    params.18, // recurrence_count
+                                    params.19, // recurrence_until
+                                    params.17, // calendar_path
                                     scope,
                                     event_data_for_update.occurrence_date.map(|d| d.format("%Y-%m-%d").to_string()), // occurrence_date
                                 )
@@ -759,6 +844,9 @@ pub fn App() -> Html {
                                             original_event.categories.join(","),
                                             reminder_str.clone(),
                                             recurrence_str.clone(),
+                                            vec![false; 7],
+                                            None,
+                                            None,
                                             original_event.calendar_path.clone(),
                                             scope.clone(),
                                             occurrence_date,
@@ -918,11 +1006,146 @@ pub fn App() -> Html {
                                         let create_modal_open = create_modal_open.clone();
                                         move |_| create_modal_open.set(true)
                                     })}
+                                    on_create_external_calendar={Callback::from({
+                                        let external_calendar_modal_open = external_calendar_modal_open.clone();
+                                        move |_| external_calendar_modal_open.set(true)
+                                    })}
+                                    external_calendars={(*external_calendars).clone()}
+                                    on_external_calendar_toggle={Callback::from({
+                                        let external_calendars = external_calendars.clone();
+                                        let external_calendar_events = external_calendar_events.clone();
+                                        move |id: i32| {
+                                            let external_calendars = external_calendars.clone();
+                                            let external_calendar_events = external_calendar_events.clone();
+                                            wasm_bindgen_futures::spawn_local(async move {
+                                                // Find the calendar and toggle its visibility
+                                                let mut calendars = (*external_calendars).clone();
+                                                if let Some(calendar) = calendars.iter_mut().find(|c| c.id == id) {
+                                                    calendar.is_visible = !calendar.is_visible;
+                                                    
+                                                    // Update on server
+                                                    if let Err(err) = CalendarService::update_external_calendar(
+                                                        calendar.id,
+                                                        &calendar.name,
+                                                        &calendar.url,
+                                                        &calendar.color,
+                                                        calendar.is_visible,
+                                                    ).await {
+                                                        web_sys::console::log_1(
+                                                            &format!("Failed to update external calendar: {}", err).into(),
+                                                        );
+                                                        return;
+                                                    }
+                                                    
+                                                    external_calendars.set(calendars.clone());
+                                                    
+                                                    // Reload events for all visible external calendars  
+                                                    let mut all_events = Vec::new();
+                                                    for cal in calendars {
+                                                        if cal.is_visible {
+                                                            if let Ok(mut events) = CalendarService::fetch_external_calendar_events(cal.id).await {
+                                                                // Set calendar_path for color matching
+                                                                for event in &mut events {
+                                                                    event.calendar_path = Some(format!("external_{}", cal.id));
+                                                                }
+                                                                all_events.extend(events);
+                                                            }
+                                                        }
+                                                    }
+                                                    external_calendar_events.set(all_events);
+                                                }
+                                            });
+                                        }
+                                    })}
+                                    on_external_calendar_delete={Callback::from({
+                                        let external_calendars = external_calendars.clone();
+                                        let external_calendar_events = external_calendar_events.clone();
+                                        move |id: i32| {
+                                            let external_calendars = external_calendars.clone();
+                                            let external_calendar_events = external_calendar_events.clone();
+                                            wasm_bindgen_futures::spawn_local(async move {
+                                                // Delete the external calendar from the server
+                                                if let Err(err) = CalendarService::delete_external_calendar(id).await {
+                                                    web_sys::console::log_1(
+                                                        &format!("Failed to delete external calendar: {}", err).into(),
+                                                    );
+                                                    return;
+                                                }
+                                                
+                                                // Remove calendar from local state
+                                                let mut calendars = (*external_calendars).clone();
+                                                calendars.retain(|c| c.id != id);
+                                                external_calendars.set(calendars.clone());
+                                                
+                                                // Remove events from this calendar
+                                                let mut events = (*external_calendar_events).clone();
+                                                events.retain(|e| {
+                                                    if let Some(ref calendar_path) = e.calendar_path {
+                                                        calendar_path != &format!("external_{}", id)
+                                                    } else {
+                                                        true
+                                                    }
+                                                });
+                                                external_calendar_events.set(events);
+                                            });
+                                        }
+                                    })}
+                                    on_external_calendar_refresh={Callback::from({
+                                        let external_calendar_events = external_calendar_events.clone();
+                                        let external_calendars = external_calendars.clone();
+                                        move |id: i32| {
+                                            let external_calendar_events = external_calendar_events.clone();
+                                            let external_calendars = external_calendars.clone();
+                                            wasm_bindgen_futures::spawn_local(async move {
+                                                // Force refresh of this specific calendar
+                                                if let Ok(mut events) = CalendarService::fetch_external_calendar_events(id).await {
+                                                    // Set calendar_path for color matching
+                                                    for event in &mut events {
+                                                        event.calendar_path = Some(format!("external_{}", id));
+                                                    }
+                                                    
+                                                    // Update events for this calendar
+                                                    let mut all_events = (*external_calendar_events).clone();
+                                                    // Remove old events from this calendar
+                                                    all_events.retain(|e| {
+                                                        if let Some(ref calendar_path) = e.calendar_path {
+                                                            calendar_path != &format!("external_{}", id)
+                                                        } else {
+                                                            true
+                                                        }
+                                                    });
+                                                    // Add new events
+                                                    all_events.extend(events);
+                                                    external_calendar_events.set(all_events);
+                                                    
+                                                    // Update the last_fetched timestamp in calendars list
+                                                    if let Ok(calendars) = CalendarService::get_external_calendars().await {
+                                                        external_calendars.set(calendars);
+                                                    }
+                                                }
+                                            });
+                                        }
+                                    })}
                                     color_picker_open={(*color_picker_open).clone()}
                                     on_color_change={on_color_change}
                                     on_color_picker_toggle={on_color_picker_toggle}
                                     available_colors={(*available_colors).clone()}
                                     on_calendar_context_menu={on_calendar_context_menu}
+                                    on_calendar_visibility_toggle={Callback::from({
+                                        let user_info = user_info.clone();
+                                        move |calendar_path: String| {
+                                            let user_info = user_info.clone();
+                                            wasm_bindgen_futures::spawn_local(async move {
+                                                if let Some(mut info) = (*user_info).clone() {
+                                                    // Toggle the visibility
+                                                    if let Some(calendar) = info.calendars.iter_mut().find(|c| c.path == calendar_path) {
+                                                        calendar.is_visible = !calendar.is_visible;
+                                                        user_info.set(Some(info));
+                                                    }
+                                                }
+                                            });
+                                        }
+                                    })}
                                     current_view={(*current_view).clone()}
                                     on_view_change={on_view_change}
                                     current_theme={(*current_theme).clone()}
@@ -935,6 +1158,8 @@ pub fn App() -> Html {
                                         auth_token={(*auth_token).clone()}
                                         user_info={(*user_info).clone()}
                                         on_login={on_login.clone()}
+                                        external_calendar_events={(*external_calendar_events).clone()}
+                                        external_calendars={(*external_calendars).clone()}
                                         on_event_context_menu={Some(on_event_context_menu.clone())}
                                         on_calendar_context_menu={Some(on_calendar_date_context_menu.clone())}
                                         view={(*current_view).clone()}
@@ -1187,6 +1412,59 @@ pub fn App() -> Html {
                     on_create={on_event_create}
                     available_calendars={user_info.as_ref().map(|ui| ui.calendars.clone()).unwrap_or_default()}
                 />
+
+                <ExternalCalendarModal
+                    is_open={*external_calendar_modal_open}
+                    on_close={Callback::from({
+                        let external_calendar_modal_open = external_calendar_modal_open.clone();
+                        move |_| external_calendar_modal_open.set(false)
+                    })}
+                    on_success={Callback::from({
+                        let external_calendars = external_calendars.clone();
+                        let external_calendar_events = external_calendar_events.clone();
+                        move |new_calendar_id: i32| {
+                            let external_calendars = external_calendars.clone();
+                            let external_calendar_events = external_calendar_events.clone();
+                            wasm_bindgen_futures::spawn_local(async move {
+                                // First, refresh the calendar list to get the new calendar
+                                match CalendarService::get_external_calendars().await {
+                                    Ok(calendars) => {
+                                        external_calendars.set(calendars.clone());
+                                        
+                                        // Then immediately fetch events for the new calendar if it's visible
+                                        if let Some(new_calendar) = calendars.iter().find(|c| c.id == new_calendar_id) {
+                                            if new_calendar.is_visible {
+                                                match CalendarService::fetch_external_calendar_events(new_calendar_id).await {
+                                                    Ok(mut events) => {
+                                                        // Set calendar_path for color matching
+                                                        for event in &mut events {
+                                                            event.calendar_path = Some(format!("external_{}", new_calendar_id));
+                                                        }
+                                                        
+                                                        // Add the new calendar's events to existing events
+                                                        let mut all_events = (*external_calendar_events).clone();
+                                                        all_events.extend(events);
+                                                        external_calendar_events.set(all_events);
+                                                    }
+                                                    Err(e) => {
+                                                        web_sys::console::log_1(
+                                                            &format!("Failed to fetch events for new calendar {}: {}", new_calendar_id, e).into(),
+                                                        );
+                                                    }
+                                                }
+                                            }
+                                        }
+                                    }
+                                    Err(err) => {
+                                        web_sys::console::log_1(
+                                            &format!("Failed to refresh calendars after creation: {}", err).into(),
+                                        );
+                                    }
+                                }
+                            });
+                        }
+                    })}
+                />
             </div>
         </BrowserRouter>
     }

frontend/src/components/calendar.rs

@@ -2,7 +2,7 @@ use crate::components::{
     CalendarHeader, CreateEventModal, EventCreationData, EventModal, MonthView, ViewMode, WeekView,
 };
 use crate::models::ical::VEvent;
-use crate::services::{calendar_service::UserInfo, CalendarService};
+use crate::services::{calendar_service::{UserInfo, ExternalCalendar}, CalendarService};
 use chrono::{Datelike, Duration, Local, NaiveDate};
 use gloo_storage::{LocalStorage, Storage};
 use std::collections::HashMap;
@@ -14,6 +14,10 @@ pub struct CalendarProps {
     #[prop_or_default]
     pub user_info: Option<UserInfo>,
     #[prop_or_default]
+    pub external_calendar_events: Vec<VEvent>,
+    #[prop_or_default]
+    pub external_calendars: Vec<ExternalCalendar>,
+    #[prop_or_default]
     pub on_event_context_menu: Option<Callback<(web_sys::MouseEvent, VEvent)>>,
     #[prop_or_default]
     pub on_calendar_context_menu: Option<Callback<(web_sys::MouseEvent, NaiveDate)>>,
@@ -101,10 +105,14 @@ pub fn Calendar(props: &CalendarProps) -> Html {
         let loading = loading.clone();
         let error = error.clone();
         let current_date = current_date.clone();
+        let external_events = props.external_calendar_events.clone(); // Clone before the effect
+        let view = props.view.clone(); // Clone before the effect
         
-        use_effect_with((*current_date, props.view.clone()), move |(date, _view)| {
+        use_effect_with((*current_date, view.clone(), external_events.len(), props.user_info.clone()), move |(date, _view, _external_len, user_info)| {
             let auth_token: Option<String> = LocalStorage::get("auth_token").ok();
             let date = *date; // Clone the date to avoid lifetime issues
+            let external_events = external_events.clone(); // Clone external events to avoid lifetime issues
+            let user_info = user_info.clone(); // Clone user_info to avoid lifetime issues
             
             if let Some(token) = auth_token {
                 let events = events.clone();
@@ -141,7 +149,38 @@ pub fn Calendar(props: &CalendarProps) -> Html {
                         .await
                     {
                         Ok(vevents) => {
-                            let grouped_events = CalendarService::group_events_by_date(vevents);
+                            // Filter CalDAV events based on calendar visibility
+                            let mut filtered_events = if let Some(user_info) = user_info.as_ref() {
+                                vevents.into_iter()
+                                    .filter(|event| {
+                                        if let Some(calendar_path) = event.calendar_path.as_ref() {
+                                            // Find the calendar info for this event
+                                            user_info.calendars.iter()
+                                                .find(|cal| &cal.path == calendar_path)
+                                                .map(|cal| cal.is_visible)
+                                                .unwrap_or(true) // Default to visible if not found
+                                        } else {
+                                            true // Show events without calendar path
+                                        }
+                                    })
+                                    .collect()
+                            } else {
+                                vevents // Show all events if no user info
+                            };
+                            
+                            // Mark external events as external by adding a special category
+                            let marked_external_events: Vec<VEvent> = external_events
+                                .into_iter()
+                                .map(|mut event| {
+                                    // Add a special category to identify external events
+                                    event.categories.push("__EXTERNAL_CALENDAR__".to_string());
+                                    event
+                                })
+                                .collect();
+                            
+                            filtered_events.extend(marked_external_events);
+                            
+                            let grouped_events = CalendarService::group_events_by_date(filtered_events);
                             events.set(grouped_events);
                             loading.set(false);
                         }
@@ -452,6 +491,7 @@ pub fn Calendar(props: &CalendarProps) -> Html {
                                 on_event_click={on_event_click.clone()}
                                 refreshing_event_uid={(*refreshing_event_uid).clone()}
                                 user_info={props.user_info.clone()}
+                                external_calendars={props.external_calendars.clone()}
                                 on_event_context_menu={props.on_event_context_menu.clone()}
                                 on_calendar_context_menu={props.on_calendar_context_menu.clone()}
                                 selected_date={Some(*selected_date)}
@@ -467,6 +507,7 @@ pub fn Calendar(props: &CalendarProps) -> Html {
                             on_event_click={on_event_click.clone()}
                             refreshing_event_uid={(*refreshing_event_uid).clone()}
                             user_info={props.user_info.clone()}
+                            external_calendars={props.external_calendars.clone()}
                             on_event_context_menu={props.on_event_context_menu.clone()}
                             on_calendar_context_menu={props.on_calendar_context_menu.clone()}
                             on_create_event={Some(on_create_event)}

frontend/src/components/calendar_list_item.rs

@@ -10,6 +10,7 @@ pub struct CalendarListItemProps {
     pub on_color_picker_toggle: Callback<String>,    // calendar_path
     pub available_colors: Vec<String>,
     pub on_context_menu: Callback<(MouseEvent, String)>, // (event, calendar_path)
+    pub on_visibility_toggle: Callback<String>,      // calendar_path
 }
 
 #[function_component(CalendarListItem)]
@@ -32,44 +33,59 @@ pub fn calendar_list_item(props: &CalendarListItemProps) -> Html {
         })
     };
 
+    let on_visibility_toggle = {
+        let cal_path = props.calendar.path.clone();
+        let on_visibility_toggle = props.on_visibility_toggle.clone();
+        Callback::from(move |_| {
+            on_visibility_toggle.emit(cal_path.clone());
+        })
+    };
+
     html! {
         <li key={props.calendar.path.clone()} oncontextmenu={on_context_menu}>
-            <span class="calendar-color"
+            <div class="calendar-info">
-                  style={format!("background-color: {}", props.calendar.color)}
+                <input
-                  onclick={on_color_click}>
+                    type="checkbox"
-                {
+                    checked={props.calendar.is_visible}
-                    if props.color_picker_open {
+                    onchange={on_visibility_toggle}
-                        html! {
+                />
-                            <div class="color-picker">
+                <span class="calendar-color"
-                                {
+                      style={format!("background-color: {}", props.calendar.color)}
-                                    props.available_colors.iter().map(|color| {
+                      onclick={on_color_click}>
-                                        let color_str = color.clone();
+                    {
-                                        let cal_path = props.calendar.path.clone();
+                        if props.color_picker_open {
-                                        let on_color_change = props.on_color_change.clone();
+                            html! {
+                                <div class="color-picker">
+                                    {
+                                        props.available_colors.iter().map(|color| {
+                                            let color_str = color.clone();
+                                            let cal_path = props.calendar.path.clone();
+                                            let on_color_change = props.on_color_change.clone();
 
-                                        let on_color_select = Callback::from(move |_: MouseEvent| {
+                                            let on_color_select = Callback::from(move |_: MouseEvent| {
-                                            on_color_change.emit((cal_path.clone(), color_str.clone()));
+                                                on_color_change.emit((cal_path.clone(), color_str.clone()));
-                                        });
+                                            });
 
-                                        let is_selected = props.calendar.color == *color;
+                                            let is_selected = props.calendar.color == *color;
-                                        let class_name = if is_selected { "color-option selected" } else { "color-option" };
+                                            let class_name = if is_selected { "color-option selected" } else { "color-option" };
 
-                                        html! {
+                                            html! {
-                                            <div class={class_name}
+                                                <div class={class_name}
-                                                 style={format!("background-color: {}", color)}
+                                                     style={format!("background-color: {}", color)}
-                                                 onclick={on_color_select}>
+                                                     onclick={on_color_select}>
-                                            </div>
+                                                </div>
-                                        }
+                                            }
-                                    }).collect::<Html>()
+                                        }).collect::<Html>()
-                                }
+                                    }
-                            </div>
+                                </div>
+                            }
+                        } else {
+                            html! {}
                         }
-                    } else {
-                        html! {}
                     }
-                }
+                </span>
-            </span>
+                <span class="calendar-name">{&props.calendar.display_name}</span>
-            <span class="calendar-name">{&props.calendar.display_name}</span>
+            </div>
         </li>
     }
 }

frontend/src/components/create_event_modal.rs

@@ -290,16 +290,32 @@ fn vevent_to_creation_data(event: &crate::models::ical::VEvent, available_calend
         // Reminders - TODO: Parse alarm from VEvent if needed
         reminder: ReminderType::None,
         
-        // Recurrence - TODO: Parse RRULE if needed for advanced editing
+        // Recurrence - Parse RRULE if present
-        recurrence: if event.rrule.is_some() {
+        recurrence: if let Some(ref rrule_str) = event.rrule {
-            RecurrenceType::Daily // Default, could be enhanced to parse actual RRULE
+            parse_rrule_frequency(rrule_str)
         } else {
             RecurrenceType::None
         },
-        recurrence_interval: 1,
+        recurrence_interval: if let Some(ref rrule_str) = event.rrule {
-        recurrence_until: None,
+            parse_rrule_interval(rrule_str)
-        recurrence_count: None,
+        } else {
-        recurrence_days: vec![false; 7],
+            1
+        },
+        recurrence_until: if let Some(ref rrule_str) = event.rrule {
+            parse_rrule_until(rrule_str)
+        } else {
+            None
+        },
+        recurrence_count: if let Some(ref rrule_str) = event.rrule {
+            parse_rrule_count(rrule_str)
+        } else {
+            None
+        },
+        recurrence_days: if let Some(ref rrule_str) = event.rrule {
+            parse_rrule_days(rrule_str)
+        } else {
+            vec![false; 7]
+        },
         
         // Advanced recurrence
         monthly_by_day: None,
@@ -328,3 +344,112 @@ fn vevent_to_creation_data(event: &crate::models::ical::VEvent, available_calend
         occurrence_date: Some(start_local.date()), // The occurrence date being edited
     }
 }
+
+// Parse RRULE frequency component
+fn parse_rrule_frequency(rrule: &str) -> RecurrenceType {
+    if rrule.contains("FREQ=DAILY") {
+        RecurrenceType::Daily
+    } else if rrule.contains("FREQ=WEEKLY") {
+        RecurrenceType::Weekly
+    } else if rrule.contains("FREQ=MONTHLY") {
+        RecurrenceType::Monthly
+    } else if rrule.contains("FREQ=YEARLY") {
+        RecurrenceType::Yearly
+    } else {
+        RecurrenceType::None
+    }
+}
+
+// Parse RRULE interval component
+fn parse_rrule_interval(rrule: &str) -> u32 {
+    if let Some(start) = rrule.find("INTERVAL=") {
+        let interval_part = &rrule[start + 9..];
+        if let Some(end) = interval_part.find(';') {
+            interval_part[..end].parse().unwrap_or(1)
+        } else {
+            interval_part.parse().unwrap_or(1)
+        }
+    } else {
+        1
+    }
+}
+
+// Parse RRULE count component
+fn parse_rrule_count(rrule: &str) -> Option<u32> {
+    if let Some(start) = rrule.find("COUNT=") {
+        let count_part = &rrule[start + 6..];
+        if let Some(end) = count_part.find(';') {
+            count_part[..end].parse().ok()
+        } else {
+            count_part.parse().ok()
+        }
+    } else {
+        None
+    }
+}
+
+// Parse RRULE until component
+fn parse_rrule_until(rrule: &str) -> Option<chrono::NaiveDate> {
+    if let Some(start) = rrule.find("UNTIL=") {
+        let until_part = &rrule[start + 6..];
+        let until_str = if let Some(end) = until_part.find(';') {
+            &until_part[..end]
+        } else {
+            until_part
+        };
+        
+        // UNTIL can be in format YYYYMMDD or YYYYMMDDTHHMMSSZ
+        let date_part = if until_str.len() >= 8 {
+            &until_str[..8]
+        } else {
+            until_str
+        };
+        
+        // Parse YYYYMMDD format
+        if date_part.len() == 8 {
+            if let (Ok(year), Ok(month), Ok(day)) = (
+                date_part[0..4].parse::<i32>(),
+                date_part[4..6].parse::<u32>(),
+                date_part[6..8].parse::<u32>(),
+            ) {
+                chrono::NaiveDate::from_ymd_opt(year, month, day)
+            } else {
+                None
+            }
+        } else {
+            None
+        }
+    } else {
+        None
+    }
+}
+
+// Parse RRULE BYDAY component for weekly recurrence
+fn parse_rrule_days(rrule: &str) -> Vec<bool> {
+    let mut days = vec![false; 7]; // [Sun, Mon, Tue, Wed, Thu, Fri, Sat]
+    
+    if let Some(start) = rrule.find("BYDAY=") {
+        let byday_part = &rrule[start + 6..];
+        let byday_str = if let Some(end) = byday_part.find(';') {
+            &byday_part[..end]
+        } else {
+            byday_part
+        };
+        
+        // Parse comma-separated day codes: SU,MO,TU,WE,TH,FR,SA
+        for day_code in byday_str.split(',') {
+            match day_code.trim() {
+                "SU" => days[0] = true, // Sunday
+                "MO" => days[1] = true, // Monday
+                "TU" => days[2] = true, // Tuesday
+                "WE" => days[3] = true, // Wednesday
+                "TH" => days[4] = true, // Thursday
+                "FR" => days[5] = true, // Friday
+                "SA" => days[6] = true, // Saturday
+                _ => {} // Ignore unknown day codes
+            }
+        }
+    }
+    
+    days
+}

frontend/src/components/external_calendar_modal.rs

@@ -0,0 +1,222 @@
+use web_sys::HtmlInputElement;
+use yew::prelude::*;
+
+use crate::services::calendar_service::CalendarService;
+
+#[derive(Properties, PartialEq)]
+pub struct ExternalCalendarModalProps {
+    pub is_open: bool,
+    pub on_close: Callback<()>,
+    pub on_success: Callback<i32>, // Pass the newly created calendar ID
+}
+
+#[function_component(ExternalCalendarModal)]
+pub fn external_calendar_modal(props: &ExternalCalendarModalProps) -> Html {
+    let name_ref = use_node_ref();
+    let url_ref = use_node_ref();
+    let color_ref = use_node_ref();
+    let is_loading = use_state(|| false);
+    let error_message = use_state(|| None::<String>);
+
+    let on_submit = {
+        let name_ref = name_ref.clone();
+        let url_ref = url_ref.clone();
+        let color_ref = color_ref.clone();
+        let is_loading = is_loading.clone();
+        let error_message = error_message.clone();
+        let on_close = props.on_close.clone();
+        let on_success = props.on_success.clone();
+
+        Callback::from(move |e: SubmitEvent| {
+            e.prevent_default();
+            
+            let name = name_ref
+                .cast::<HtmlInputElement>()
+                .map(|input| input.value())
+                .unwrap_or_default()
+                .trim()
+                .to_string();
+            
+            let url = url_ref
+                .cast::<HtmlInputElement>()
+                .map(|input| input.value())
+                .unwrap_or_default()
+                .trim()
+                .to_string();
+                
+            let color = color_ref
+                .cast::<HtmlInputElement>()
+                .map(|input| input.value())
+                .unwrap_or_else(|| "#4285f4".to_string());
+
+            if name.is_empty() {
+                error_message.set(Some("Calendar name is required".to_string()));
+                return;
+            }
+
+            if url.is_empty() {
+                error_message.set(Some("Calendar URL is required".to_string()));
+                return;
+            }
+
+            // Basic URL validation
+            if !url.starts_with("http://") && !url.starts_with("https://") {
+                error_message.set(Some("Please enter a valid HTTP or HTTPS URL".to_string()));
+                return;
+            }
+
+            error_message.set(None);
+            is_loading.set(true);
+
+            let is_loading = is_loading.clone();
+            let error_message = error_message.clone();
+            let on_close = on_close.clone();
+            let on_success = on_success.clone();
+
+            wasm_bindgen_futures::spawn_local(async move {
+                match CalendarService::create_external_calendar(&name, &url, &color).await {
+                    Ok(new_calendar) => {
+                        is_loading.set(false);
+                        on_success.emit(new_calendar.id);
+                        on_close.emit(());
+                    }
+                    Err(e) => {
+                        is_loading.set(false);
+                        error_message.set(Some(format!("Failed to add calendar: {}", e)));
+                    }
+                }
+            });
+        })
+    };
+
+    let on_cancel = {
+        let on_close = props.on_close.clone();
+        Callback::from(move |_| {
+            on_close.emit(());
+        })
+    };
+    
+    let on_cancel_clone = on_cancel.clone();
+
+    if !props.is_open {
+        return html! {};
+    }
+
+    html! {
+        <div class="modal-backdrop" onclick={on_cancel_clone}>
+            <div class="external-calendar-modal" onclick={Callback::from(|e: MouseEvent| e.stop_propagation())}>
+                <div class="modal-header">
+                    <h3>{"Add External Calendar"}</h3>
+                    <button class="modal-close" onclick={on_cancel.clone()}>{"×"}</button>
+                </div>
+                
+                <form onsubmit={on_submit}>
+                    <div class="modal-body">
+                        {
+                            if let Some(error) = (*error_message).as_ref() {
+                                html! {
+                                    <div class="error-message">
+                                        {error}
+                                    </div>
+                                }
+                            } else {
+                                html! {}
+                            }
+                        }
+                        
+                        <div class="form-help" style="margin-bottom: 1.5rem; padding: 1rem; background: #f8f9fa; border-radius: 8px; border-left: 4px solid #007bff;">
+                            <h4 style="margin: 0 0 0.5rem 0; font-size: 0.9rem; color: #495057;">{"Setting up External Calendars"}</h4>
+                            <p style="margin: 0 0 0.5rem 0; font-size: 0.8rem; line-height: 1.4;">
+                                {"Currently tested with Outlook 365 and Google Calendar. To get your calendar link:"}
+                            </p>
+                            
+                            <div style="margin-bottom: 1rem;">
+                                <strong style="font-size: 0.8rem; color: #495057;">{"Outlook 365:"}</strong>
+                                <ol style="margin: 0.3rem 0 0 0; padding-left: 1.2rem; font-size: 0.8rem; line-height: 1.3;">
+                                    <li>{"Go to Outlook Settings"}</li>
+                                    <li>{"Navigate to Calendar → Shared Calendars"}</li>
+                                    <li>{"Click \"Publish a calendar\""}</li>
+                                    <li>{"Select your calendar and choose \"Can view all details\""}</li>
+                                    <li>{"Copy the ICS link and paste it below"}</li>
+                                </ol>
+                            </div>
+                            
+                            <div>
+                                <strong style="font-size: 0.8rem; color: #495057;">{"Google Calendar:"}</strong>
+                                <ol style="margin: 0.3rem 0 0 0; padding-left: 1.2rem; font-size: 0.8rem; line-height: 1.3;">
+                                    <li>{"Hover over your calendar name in the left sidebar"}</li>
+                                    <li>{"Click the three dots that appear"}</li>
+                                    <li>{"Select \"Settings and sharing\""}</li>
+                                    <li>{"Scroll to \"Integrate calendar\""}</li>
+                                    <li>{"Copy the \"Public address in iCal format\" link"}</li>
+                                </ol>
+                            </div>
+                        </div>
+                        
+                        <div class="form-group">
+                            <label for="external-calendar-name">{"Calendar Name"}</label>
+                            <input
+                                ref={name_ref}
+                                id="external-calendar-name"
+                                type="text"
+                                placeholder="My External Calendar"
+                                disabled={*is_loading}
+                                required={true}
+                            />
+                        </div>
+
+                        <div class="form-group">
+                            <label for="external-calendar-url">{"ICS URL"}</label>
+                            <input
+                                ref={url_ref}
+                                id="external-calendar-url"
+                                type="url"
+                                placeholder="https://example.com/calendar.ics"
+                                disabled={*is_loading}
+                                required={true}
+                            />
+                            <small class="form-help">
+                                {"Enter the public ICS URL for the calendar you want to add"}
+                            </small>
+                        </div>
+
+                        <div class="form-group">
+                            <label for="external-calendar-color">{"Color"}</label>
+                            <input
+                                ref={color_ref}
+                                id="external-calendar-color"
+                                type="color"
+                                value="#4285f4"
+                                disabled={*is_loading}
+                            />
+                        </div>
+                    </div>
+
+                    <div class="modal-actions">
+                        <button
+                            type="button"
+                            class="btn btn-secondary"
+                            onclick={on_cancel}
+                            disabled={*is_loading}
+                        >
+                            {"Cancel"}
+                        </button>
+                        <button
+                            type="submit"
+                            class="btn btn-primary"
+                            disabled={*is_loading}
+                        >
+                            {
+                                if *is_loading {
+                                    "Adding..."
+                                } else {
+                                    "Add Calendar"
+                                }
+                            }
+                        </button>
+                    </div>
+                </form>
+            </div>
+        </div>
+    }
+}

frontend/src/components/mod.rs

@@ -8,6 +8,7 @@ pub mod create_event_modal;
 pub mod event_context_menu;
 pub mod event_form;
 pub mod event_modal;
+pub mod external_calendar_modal;
 pub mod login;
 pub mod month_view;
 pub mod recurring_edit_modal;
@@ -26,6 +27,7 @@ pub use create_event_modal::CreateEventModal;
 pub use event_form::EventCreationData;
 pub use event_context_menu::{DeleteAction, EditAction, EventContextMenu};
 pub use event_modal::EventModal;
+pub use external_calendar_modal::ExternalCalendarModal;
 pub use login::Login;
 pub use month_view::MonthView;
 pub use recurring_edit_modal::{RecurringEditAction, RecurringEditModal};

frontend/src/components/month_view.rs

@@ -1,5 +1,5 @@
 use crate::models::ical::VEvent;
-use crate::services::calendar_service::UserInfo;
+use crate::services::calendar_service::{UserInfo, ExternalCalendar};
 use chrono::{Datelike, NaiveDate, Weekday};
 use std::collections::HashMap;
 use wasm_bindgen::{prelude::*, JsCast};
@@ -17,6 +17,8 @@ pub struct MonthViewProps {
     #[prop_or_default]
     pub user_info: Option<UserInfo>,
     #[prop_or_default]
+    pub external_calendars: Vec<ExternalCalendar>,
+    #[prop_or_default]
     pub on_event_context_menu: Option<Callback<(web_sys::MouseEvent, VEvent)>>,
     #[prop_or_default]
     pub on_calendar_context_menu: Option<Callback<(web_sys::MouseEvent, NaiveDate)>>,
@@ -85,8 +87,20 @@ pub fn month_view(props: &MonthViewProps) -> Html {
 
     // Helper function to get calendar color for an event
     let get_event_color = |event: &VEvent| -> String {
-        if let Some(user_info) = &props.user_info {
+        if let Some(calendar_path) = &event.calendar_path {
-            if let Some(calendar_path) = &event.calendar_path {
+            // Check external calendars first (path format: "external_{id}")
+            if calendar_path.starts_with("external_") {
+                if let Ok(id_str) = calendar_path.strip_prefix("external_").unwrap_or("").parse::<i32>() {
+                    if let Some(external_calendar) = props.external_calendars
+                        .iter()
+                        .find(|cal| cal.id == id_str)
+                    {
+                        return external_calendar.color.clone();
+                    }
+                }
+            }
+            // Check regular calendars
+            else if let Some(user_info) = &props.user_info {
                 if let Some(calendar) = user_info
                     .calendars
                     .iter()
@@ -194,6 +208,7 @@ pub fn month_view(props: &MonthViewProps) -> Html {
                                             <div
                                                 class={classes!("event-box", if is_refreshing { Some("refreshing") } else { None })}
                                                 style={format!("background-color: {}", event_color)}
+                                                data-external={event.categories.contains(&"__EXTERNAL_CALENDAR__".to_string()).to_string()}
                                                 {onclick}
                                                 {oncontextmenu}
                                             >

frontend/src/components/route_handler.rs

@@ -1,6 +1,6 @@
 use crate::components::{Login, ViewMode};
 use crate::models::ical::VEvent;
-use crate::services::calendar_service::UserInfo;
+use crate::services::calendar_service::{UserInfo, ExternalCalendar};
 use yew::prelude::*;
 use yew_router::prelude::*;
 
@@ -20,6 +20,10 @@ pub struct RouteHandlerProps {
     pub user_info: Option<UserInfo>,
     pub on_login: Callback<String>,
     #[prop_or_default]
+    pub external_calendar_events: Vec<VEvent>,
+    #[prop_or_default]
+    pub external_calendars: Vec<ExternalCalendar>,
+    #[prop_or_default]
     pub on_event_context_menu: Option<Callback<(web_sys::MouseEvent, VEvent)>>,
     #[prop_or_default]
     pub on_calendar_context_menu: Option<Callback<(web_sys::MouseEvent, chrono::NaiveDate)>>,
@@ -48,6 +52,8 @@ pub fn route_handler(props: &RouteHandlerProps) -> Html {
     let auth_token = props.auth_token.clone();
     let user_info = props.user_info.clone();
     let on_login = props.on_login.clone();
+    let external_calendar_events = props.external_calendar_events.clone();
+    let external_calendars = props.external_calendars.clone();
     let on_event_context_menu = props.on_event_context_menu.clone();
     let on_calendar_context_menu = props.on_calendar_context_menu.clone();
     let view = props.view.clone();
@@ -60,6 +66,8 @@ pub fn route_handler(props: &RouteHandlerProps) -> Html {
             let auth_token = auth_token.clone();
             let user_info = user_info.clone();
             let on_login = on_login.clone();
+            let external_calendar_events = external_calendar_events.clone();
+            let external_calendars = external_calendars.clone();
             let on_event_context_menu = on_event_context_menu.clone();
             let on_calendar_context_menu = on_calendar_context_menu.clone();
             let view = view.clone();
@@ -87,6 +95,8 @@ pub fn route_handler(props: &RouteHandlerProps) -> Html {
                         html! {
                             <CalendarView
                                 user_info={user_info}
+                                external_calendar_events={external_calendar_events}
+                                external_calendars={external_calendars}
                                 on_event_context_menu={on_event_context_menu}
                                 on_calendar_context_menu={on_calendar_context_menu}
                                 view={view}
@@ -108,6 +118,10 @@ pub fn route_handler(props: &RouteHandlerProps) -> Html {
 pub struct CalendarViewProps {
     pub user_info: Option<UserInfo>,
     #[prop_or_default]
+    pub external_calendar_events: Vec<VEvent>,
+    #[prop_or_default]
+    pub external_calendars: Vec<ExternalCalendar>,
+    #[prop_or_default]
     pub on_event_context_menu: Option<Callback<(web_sys::MouseEvent, VEvent)>>,
     #[prop_or_default]
     pub on_calendar_context_menu: Option<Callback<(web_sys::MouseEvent, chrono::NaiveDate)>>,
@@ -139,6 +153,8 @@ pub fn calendar_view(props: &CalendarViewProps) -> Html {
         <div class="calendar-view">
             <Calendar
                 user_info={props.user_info.clone()}
+                external_calendar_events={props.external_calendar_events.clone()}
+                external_calendars={props.external_calendars.clone()}
                 on_event_context_menu={props.on_event_context_menu.clone()}
                 on_calendar_context_menu={props.on_calendar_context_menu.clone()}
                 view={props.view.clone()}

frontend/src/components/sidebar.rs

@@ -1,5 +1,5 @@
 use crate::components::CalendarListItem;
-use crate::services::calendar_service::UserInfo;
+use crate::services::calendar_service::{UserInfo, ExternalCalendar};
 use web_sys::HtmlSelectElement;
 use yew::prelude::*;
 use yew_router::prelude::*;
@@ -101,11 +101,17 @@ pub struct SidebarProps {
     pub user_info: Option<UserInfo>,
     pub on_logout: Callback<()>,
     pub on_create_calendar: Callback<()>,
+    pub on_create_external_calendar: Callback<()>,
+    pub external_calendars: Vec<ExternalCalendar>,
+    pub on_external_calendar_toggle: Callback<i32>,
+    pub on_external_calendar_delete: Callback<i32>,
+    pub on_external_calendar_refresh: Callback<i32>,
     pub color_picker_open: Option<String>,
     pub on_color_change: Callback<(String, String)>,
     pub on_color_picker_toggle: Callback<String>,
     pub available_colors: Vec<String>,
     pub on_calendar_context_menu: Callback<(MouseEvent, String)>,
+    pub on_calendar_visibility_toggle: Callback<String>,
     pub current_view: ViewMode,
     pub on_view_change: Callback<ViewMode>,
     pub current_theme: Theme,
@@ -116,6 +122,7 @@ pub struct SidebarProps {
 
 #[function_component(Sidebar)]
 pub fn sidebar(props: &SidebarProps) -> Html {
+    let external_context_menu_open = use_state(|| None::<i32>);
     let on_view_change = {
         let on_view_change = props.on_view_change.clone();
         Callback::from(move |e: Event| {
@@ -155,6 +162,30 @@ pub fn sidebar(props: &SidebarProps) -> Html {
         })
     };
 
+    let on_external_calendar_context_menu = {
+        let external_context_menu_open = external_context_menu_open.clone();
+        Callback::from(move |(e, cal_id): (MouseEvent, i32)| {
+            e.prevent_default();
+            external_context_menu_open.set(Some(cal_id));
+        })
+    };
+
+    let on_external_calendar_delete = {
+        let on_external_calendar_delete = props.on_external_calendar_delete.clone();
+        let external_context_menu_open = external_context_menu_open.clone();
+        Callback::from(move |cal_id: i32| {
+            on_external_calendar_delete.emit(cal_id);
+            external_context_menu_open.set(None);
+        })
+    };
+
+    let close_external_context_menu = {
+        let external_context_menu_open = external_context_menu_open.clone();
+        Callback::from(move |_| {
+            external_context_menu_open.set(None);
+        })
+    };
+
     html! {
         <aside class="app-sidebar">
             <div class="sidebar-header">
@@ -192,6 +223,7 @@ pub fn sidebar(props: &SidebarProps) -> Html {
                                                     on_color_picker_toggle={props.on_color_picker_toggle.clone()}
                                                     available_colors={props.available_colors.clone()}
                                                     on_context_menu={props.on_calendar_context_menu.clone()}
+                                                    on_visibility_toggle={props.on_calendar_visibility_toggle.clone()}
                                                 />
                                             }
                                         }).collect::<Html>()
@@ -206,11 +238,128 @@ pub fn sidebar(props: &SidebarProps) -> Html {
                     html! {}
                 }
             }
+            
+            // External calendars section
+            <div class="external-calendar-list">
+                <h3>{"External Calendars"}</h3>
+                {
+                    if !props.external_calendars.is_empty() {
+                        html! {
+                            <ul class="external-calendar-items">
+                                {
+                                    props.external_calendars.iter().map(|cal| {
+                                        let on_toggle = {
+                                            let on_external_calendar_toggle = props.on_external_calendar_toggle.clone();
+                                            let cal_id = cal.id;
+                                            Callback::from(move |_| {
+                                                on_external_calendar_toggle.emit(cal_id);
+                                            })
+                                        };
+                                        
+                                        html! {
+                                            <li class="external-calendar-item" style="position: relative;">
+                                                <div 
+                                                    class="external-calendar-info"
+                                                    oncontextmenu={{
+                                                        let on_context_menu = on_external_calendar_context_menu.clone();
+                                                        let cal_id = cal.id;
+                                                        Callback::from(move |e: MouseEvent| {
+                                                            on_context_menu.emit((e, cal_id));
+                                                        })
+                                                    }}
+                                                >
+                                                    <input
+                                                        type="checkbox"
+                                                        checked={cal.is_visible}
+                                                        onchange={on_toggle}
+                                                    />
+                                                    <span 
+                                                        class="external-calendar-color" 
+                                                        style={format!("background-color: {}", cal.color)}
+                                                    />
+                                                    <span class="external-calendar-name">{&cal.name}</span>
+                                                    <div class="external-calendar-actions">
+                                                        {
+                                                            if let Some(last_fetched) = cal.last_fetched {
+                                                                let local_time = last_fetched.with_timezone(&chrono::Local);
+                                                                html! {
+                                                                    <span class="last-updated" title={format!("Last updated: {}", local_time.format("%Y-%m-%d %H:%M"))}>
+                                                                        {format!("{}", local_time.format("%H:%M"))}
+                                                                    </span>
+                                                                }
+                                                            } else {
+                                                                html! {
+                                                                    <span class="last-updated">{"Never"}</span>
+                                                                }
+                                                            }
+                                                        }
+                                                        <button 
+                                                            class="external-calendar-refresh-btn" 
+                                                            title="Refresh calendar"
+                                                            onclick={{
+                                                                let on_refresh = props.on_external_calendar_refresh.clone();
+                                                                let cal_id = cal.id;
+                                                                Callback::from(move |e: MouseEvent| {
+                                                                    e.stop_propagation();
+                                                                    on_refresh.emit(cal_id);
+                                                                })
+                                                            }}
+                                                        >
+                                                            {"🔄"}
+                                                        </button>
+                                                    </div>
+                                                </div>
+                                                {
+                                                    if *external_context_menu_open == Some(cal.id) {
+                                                        html! {
+                                                            <>
+                                                                <div 
+                                                                    class="context-menu-overlay" 
+                                                                    onclick={close_external_context_menu.clone()}
+                                                                    style="position: fixed; top: 0; left: 0; width: 100vw; height: 100vh; z-index: 999;"
+                                                                />
+                                                                <div class="context-menu" style="position: absolute; top: 0; right: 0; background: white; border: 1px solid #ccc; border-radius: 4px; box-shadow: 0 2px 8px rgba(0,0,0,0.15); z-index: 1000; min-width: 120px;">
+                                                                    <div 
+                                                                        class="context-menu-item" 
+                                                                        style="padding: 8px 12px; cursor: pointer; color: #d73a49;"
+                                                                        onclick={{
+                                                                            let on_delete = on_external_calendar_delete.clone();
+                                                                            let cal_id = cal.id;
+                                                                            Callback::from(move |_| {
+                                                                                on_delete.emit(cal_id);
+                                                                            })
+                                                                        }}
+                                                                    >
+                                                                        {"Delete Calendar"}
+                                                                    </div>
+                                                                </div>
+                                                            </>
+                                                        }
+                                                    } else {
+                                                        html! {}
+                                                    }
+                                                }
+                                            </li>
+                                        }
+                                    }).collect::<Html>()
+                                }
+                            </ul>
+                        }
+                    } else {
+                        html! {}
+                    }
+                }
+            </div>
+            
             <div class="sidebar-footer">
                 <button onclick={props.on_create_calendar.reform(|_| ())} class="create-calendar-button">
                     {"+ Create Calendar"}
                 </button>
                 
+                <button onclick={props.on_create_external_calendar.reform(|_| ())} class="create-external-calendar-button">
+                    {"+ Add External Calendar"}
+                </button>
+
                 <div class="view-selector">
                     <select class="view-selector-dropdown" onchange={on_view_change}>
                         <option value="month" selected={matches!(props.current_view, ViewMode::Month)}>{"Month"}</option>

frontend/src/components/week_view.rs

@@ -1,6 +1,6 @@
 use crate::components::{EventCreationData, RecurringEditAction, RecurringEditModal};
 use crate::models::ical::VEvent;
-use crate::services::calendar_service::UserInfo;
+use crate::services::calendar_service::{UserInfo, ExternalCalendar};
 use chrono::{Datelike, Duration, Local, NaiveDate, NaiveDateTime, NaiveTime, Timelike, Weekday};
 use std::collections::HashMap;
 use web_sys::MouseEvent;
@@ -17,6 +17,8 @@ pub struct WeekViewProps {
     #[prop_or_default]
     pub user_info: Option<UserInfo>,
     #[prop_or_default]
+    pub external_calendars: Vec<ExternalCalendar>,
+    #[prop_or_default]
     pub on_event_context_menu: Option<Callback<(web_sys::MouseEvent, VEvent)>>,
     #[prop_or_default]
     pub on_calendar_context_menu: Option<Callback<(web_sys::MouseEvent, NaiveDate)>>,
@@ -81,8 +83,20 @@ pub fn week_view(props: &WeekViewProps) -> Html {
 
     // Helper function to get calendar color for an event
     let get_event_color = |event: &VEvent| -> String {
-        if let Some(user_info) = &props.user_info {
+        if let Some(calendar_path) = &event.calendar_path {
-            if let Some(calendar_path) = &event.calendar_path {
+            // Check external calendars first (path format: "external_{id}")
+            if calendar_path.starts_with("external_") {
+                if let Ok(id_str) = calendar_path.strip_prefix("external_").unwrap_or("").parse::<i32>() {
+                    if let Some(external_calendar) = props.external_calendars
+                        .iter()
+                        .find(|cal| cal.id == id_str)
+                    {
+                        return external_calendar.color.clone();
+                    }
+                }
+            }
+            // Check regular calendars
+            else if let Some(user_info) = &props.user_info {
                 if let Some(calendar) = user_info
                     .calendars
                     .iter()
@@ -371,6 +385,7 @@ pub fn week_view(props: &WeekViewProps) -> Html {
                                                         <div 
                                                             class="all-day-event"
                                                             style={format!("background-color: {}", event_color)}
+                                                            data-external={event.categories.contains(&"__EXTERNAL_CALENDAR__".to_string()).to_string()}
                                                             {onclick}
                                                             {oncontextmenu}
                                                         >
@@ -905,6 +920,7 @@ pub fn week_view(props: &WeekViewProps) -> Html {
                                                                         column_width
                                                                     )
                                                                 }
+                                                                data-external={event.categories.contains(&"__EXTERNAL_CALENDAR__".to_string()).to_string()}
                                                                 {onclick}
                                                                 {oncontextmenu}
                                                                 onmousedown={onmousedown_event}
@@ -992,6 +1008,7 @@ pub fn week_view(props: &WeekViewProps) -> Html {
                                                                 <div
                                                                     class="temp-event-box moving-event"
                                                                     style={format!("top: {}px; height: {}px; background-color: {}; opacity: 0.7;", preview_position, duration_pixels, event_color)}
+                                                                    data-external={event.categories.contains(&"__EXTERNAL_CALENDAR__".to_string()).to_string()}
                                                                 >
                                                                     <div class="event-title">{event.summary.as_ref().unwrap_or(&"Untitled".to_string())}</div>
                                                                     {if duration_pixels > 30.0 {
@@ -1025,6 +1042,7 @@ pub fn week_view(props: &WeekViewProps) -> Html {
                                                                 <div
                                                                     class="temp-event-box resizing-event"
                                                                     style={format!("top: {}px; height: {}px; background-color: {}; opacity: 0.7;", new_start_pixels, new_height, event_color)}
+                                                                    data-external={event.categories.contains(&"__EXTERNAL_CALENDAR__".to_string()).to_string()}
                                                                 >
                                                                     <div class="event-title">{event.summary.as_ref().unwrap_or(&"Untitled".to_string())}</div>
                                                                     {if new_height > 30.0 {
@@ -1052,6 +1070,7 @@ pub fn week_view(props: &WeekViewProps) -> Html {
                                                                 <div
                                                                     class="temp-event-box resizing-event"
                                                                     style={format!("top: {}px; height: {}px; background-color: {}; opacity: 0.7;", original_start_pixels, new_height, event_color)}
+                                                                    data-external={event.categories.contains(&"__EXTERNAL_CALENDAR__".to_string()).to_string()}
                                                                 >
                                                                     <div class="event-title">{event.summary.as_ref().unwrap_or(&"Untitled".to_string())}</div>
                                                                     {if new_height > 30.0 {
@@ -1320,11 +1339,23 @@ fn calculate_event_layout(events: &[VEvent], date: NaiveDate, time_increment: u3
 
 // Check if an all-day event spans the given date
 fn event_spans_date(event: &VEvent, date: NaiveDate) -> bool {
-    let start_date = event.dtstart.with_timezone(&Local).date_naive();
+    let start_date = if event.all_day {
+        // For all-day events, extract date directly from UTC without timezone conversion
+        // since all-day events are stored at noon UTC to avoid timezone boundary issues
+        event.dtstart.date_naive()
+    } else {
+        event.dtstart.with_timezone(&Local).date_naive()
+    };
+    
     let end_date = if let Some(dtend) = event.dtend {
-        // For all-day events, dtend is often set to the day after the last day
+        if event.all_day {
-        // So we need to subtract a day to get the actual last day of the event
+            // For all-day events, dtend is set to the day after the last day (RFC 5545)
-        dtend.with_timezone(&Local).date_naive() - chrono::Duration::days(1)
+            // Extract date directly from UTC and subtract a day to get actual last day
+            dtend.date_naive() - chrono::Duration::days(1)
+        } else {
+            // For timed events, use timezone conversion
+            dtend.with_timezone(&Local).date_naive()
+        }
     } else {
         // Single day event
         start_date

frontend/src/services/calendar_service.rs

@@ -1,4 +1,5 @@
 use chrono::{DateTime, Datelike, Duration, NaiveDate, TimeZone, Utc, Weekday};
+use gloo_storage::{LocalStorage, Storage};
 use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use wasm_bindgen::JsCast;
@@ -43,6 +44,7 @@ pub struct CalendarInfo {
     pub path: String,
     pub display_name: String,
     pub color: String,
+    pub is_visible: bool,
 }
 
 // CalendarEvent, EventStatus, and EventClass are now imported from shared library
@@ -1678,6 +1680,9 @@ impl CalendarService {
         categories: String,
         reminder: String,
         recurrence: String,
+        recurrence_days: Vec<bool>,
+        recurrence_count: Option<u32>,
+        recurrence_until: Option<String>,
         calendar_path: Option<String>,
         update_scope: String,
         occurrence_date: Option<String>,
@@ -1706,10 +1711,10 @@ impl CalendarService {
             "categories": categories,
             "reminder": reminder,
             "recurrence": recurrence,
-            "recurrence_days": vec![false; 7], // Default - could be enhanced
+            "recurrence_days": recurrence_days,
-            "recurrence_interval": 1_u32, // Default interval
+            "recurrence_interval": 1_u32, // Default interval - could be enhanced to be a parameter
-            "recurrence_end_date": None as Option<String>, // No end date by default
+            "recurrence_end_date": recurrence_until,
-            "recurrence_count": None as Option<u32>, // No count limit by default
+            "recurrence_count": recurrence_count,
             "calendar_path": calendar_path,
             "update_scope": update_scope,
             "occurrence_date": occurrence_date
@@ -1851,4 +1856,257 @@ impl CalendarService {
 
         None
     }
+
+    // ==================== EXTERNAL CALENDAR METHODS ====================
+
+    pub async fn get_external_calendars() -> Result<Vec<ExternalCalendar>, String> {
+        let token = LocalStorage::get::<String>("auth_token")
+            .map_err(|_| "No authentication token found".to_string())?;
+
+        let window = web_sys::window().ok_or("No global window exists")?;
+
+        let opts = RequestInit::new();
+        opts.set_method("GET");
+        opts.set_mode(RequestMode::Cors);
+
+        let service = Self::new();
+        let url = format!("{}/external-calendars", service.base_url);
+        let request = Request::new_with_str_and_init(&url, &opts)
+            .map_err(|e| format!("Request creation failed: {:?}", e))?;
+
+        request
+            .headers()
+            .set("Authorization", &format!("Bearer {}", token))
+            .map_err(|e| format!("Authorization header setting failed: {:?}", e))?;
+
+        let resp_value = JsFuture::from(window.fetch_with_request(&request))
+            .await
+            .map_err(|e| format!("Request failed: {:?}", e))?;
+
+        let resp: Response = resp_value
+            .dyn_into()
+            .map_err(|e| format!("Response casting failed: {:?}", e))?;
+
+        if !resp.ok() {
+            return Err(format!("HTTP error: {}", resp.status()));
+        }
+
+        let json = JsFuture::from(resp.json().unwrap())
+            .await
+            .map_err(|e| format!("JSON parsing failed: {:?}", e))?;
+
+        let external_calendars: Vec<ExternalCalendar> = serde_wasm_bindgen::from_value(json)
+            .map_err(|e| format!("Deserialization failed: {:?}", e))?;
+
+        Ok(external_calendars)
+    }
+
+    pub async fn create_external_calendar(name: &str, url: &str, color: &str) -> Result<ExternalCalendar, String> {
+        let token = LocalStorage::get::<String>("auth_token")
+            .map_err(|_| "No authentication token found".to_string())?;
+
+        let window = web_sys::window().ok_or("No global window exists")?;
+
+        let opts = RequestInit::new();
+        opts.set_method("POST");
+        opts.set_mode(RequestMode::Cors);
+
+        let body = serde_json::json!({
+            "name": name,
+            "url": url,
+            "color": color
+        });
+
+        let service = Self::new();
+        let body_string = serde_json::to_string(&body)
+            .map_err(|e| format!("JSON serialization failed: {}", e))?;
+        opts.set_body(&body_string.into());
+
+        let url = format!("{}/external-calendars", service.base_url);
+        let request = Request::new_with_str_and_init(&url, &opts)
+            .map_err(|e| format!("Request creation failed: {:?}", e))?;
+
+        request
+            .headers()
+            .set("Authorization", &format!("Bearer {}", token))
+            .map_err(|e| format!("Authorization header setting failed: {:?}", e))?;
+
+        request
+            .headers()
+            .set("Content-Type", "application/json")
+            .map_err(|e| format!("Content-Type header setting failed: {:?}", e))?;
+
+        let resp_value = JsFuture::from(window.fetch_with_request(&request))
+            .await
+            .map_err(|e| format!("Request failed: {:?}", e))?;
+
+        let resp: Response = resp_value
+            .dyn_into()
+            .map_err(|e| format!("Response casting failed: {:?}", e))?;
+
+        if !resp.ok() {
+            return Err(format!("HTTP error: {}", resp.status()));
+        }
+
+        let json = JsFuture::from(resp.json().unwrap())
+            .await
+            .map_err(|e| format!("JSON parsing failed: {:?}", e))?;
+
+        let external_calendar: ExternalCalendar = serde_wasm_bindgen::from_value(json)
+            .map_err(|e| format!("Deserialization failed: {:?}", e))?;
+
+        Ok(external_calendar)
+    }
+
+    pub async fn update_external_calendar(
+        id: i32,
+        name: &str,
+        url: &str,
+        color: &str,
+        is_visible: bool,
+    ) -> Result<(), String> {
+        let token = LocalStorage::get::<String>("auth_token")
+            .map_err(|_| "No authentication token found".to_string())?;
+
+        let window = web_sys::window().ok_or("No global window exists")?;
+
+        let opts = RequestInit::new();
+        opts.set_method("POST");
+        opts.set_mode(RequestMode::Cors);
+
+        let body = serde_json::json!({
+            "name": name,
+            "url": url,
+            "color": color,
+            "is_visible": is_visible
+        });
+
+        let service = Self::new();
+        let body_string = serde_json::to_string(&body)
+            .map_err(|e| format!("JSON serialization failed: {}", e))?;
+        opts.set_body(&body_string.into());
+
+        let url = format!("{}/external-calendars/{}", service.base_url, id);
+        let request = Request::new_with_str_and_init(&url, &opts)
+            .map_err(|e| format!("Request creation failed: {:?}", e))?;
+
+        request
+            .headers()
+            .set("Authorization", &format!("Bearer {}", token))
+            .map_err(|e| format!("Authorization header setting failed: {:?}", e))?;
+
+        request
+            .headers()
+            .set("Content-Type", "application/json")
+            .map_err(|e| format!("Content-Type header setting failed: {:?}", e))?;
+
+        let resp_value = JsFuture::from(window.fetch_with_request(&request))
+            .await
+            .map_err(|e| format!("Request failed: {:?}", e))?;
+
+        let resp: Response = resp_value
+            .dyn_into()
+            .map_err(|e| format!("Response casting failed: {:?}", e))?;
+
+        if !resp.ok() {
+            return Err(format!("HTTP error: {}", resp.status()));
+        }
+
+        Ok(())
+    }
+
+    pub async fn delete_external_calendar(id: i32) -> Result<(), String> {
+        let token = LocalStorage::get::<String>("auth_token")
+            .map_err(|_| "No authentication token found".to_string())?;
+
+        let window = web_sys::window().ok_or("No global window exists")?;
+
+        let opts = RequestInit::new();
+        opts.set_method("DELETE");
+        opts.set_mode(RequestMode::Cors);
+
+        let service = Self::new();
+        let url = format!("{}/external-calendars/{}", service.base_url, id);
+        let request = Request::new_with_str_and_init(&url, &opts)
+            .map_err(|e| format!("Request creation failed: {:?}", e))?;
+
+        request
+            .headers()
+            .set("Authorization", &format!("Bearer {}", token))
+            .map_err(|e| format!("Authorization header setting failed: {:?}", e))?;
+
+        let resp_value = JsFuture::from(window.fetch_with_request(&request))
+            .await
+            .map_err(|e| format!("Request failed: {:?}", e))?;
+
+        let resp: Response = resp_value
+            .dyn_into()
+            .map_err(|e| format!("Response casting failed: {:?}", e))?;
+
+        if !resp.ok() {
+            return Err(format!("HTTP error: {}", resp.status()));
+        }
+
+        Ok(())
+    }
+
+    pub async fn fetch_external_calendar_events(id: i32) -> Result<Vec<VEvent>, String> {
+        let token = LocalStorage::get::<String>("auth_token")
+            .map_err(|_| "No authentication token found".to_string())?;
+
+        let window = web_sys::window().ok_or("No global window exists")?;
+
+        let opts = RequestInit::new();
+        opts.set_method("GET");
+        opts.set_mode(RequestMode::Cors);
+
+        let service = Self::new();
+        let url = format!("{}/external-calendars/{}/events", service.base_url, id);
+        let request = Request::new_with_str_and_init(&url, &opts)
+            .map_err(|e| format!("Request creation failed: {:?}", e))?;
+
+        request
+            .headers()
+            .set("Authorization", &format!("Bearer {}", token))
+            .map_err(|e| format!("Authorization header setting failed: {:?}", e))?;
+
+        let resp_value = JsFuture::from(window.fetch_with_request(&request))
+            .await
+            .map_err(|e| format!("Request failed: {:?}", e))?;
+
+        let resp: Response = resp_value
+            .dyn_into()
+            .map_err(|e| format!("Response casting failed: {:?}", e))?;
+
+        if !resp.ok() {
+            return Err(format!("HTTP error: {}", resp.status()));
+        }
+
+        let json = JsFuture::from(resp.json().unwrap())
+            .await
+            .map_err(|e| format!("JSON parsing failed: {:?}", e))?;
+
+        #[derive(Deserialize)]
+        struct ExternalCalendarEventsResponse {
+            events: Vec<VEvent>,
+            last_fetched: chrono::DateTime<chrono::Utc>,
+        }
+
+        let response: ExternalCalendarEventsResponse = serde_wasm_bindgen::from_value(json)
+            .map_err(|e| format!("Deserialization failed: {:?}", e))?;
+
+        Ok(response.events)
+    }
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
+pub struct ExternalCalendar {
+    pub id: i32,
+    pub name: String,
+    pub url: String,
+    pub color: String,
+    pub is_visible: bool,
+    pub created_at: chrono::DateTime<chrono::Utc>,
+    pub updated_at: chrono::DateTime<chrono::Utc>,
+    pub last_fetched: Option<chrono::DateTime<chrono::Utc>>,
 }

frontend/styles.css

@@ -3745,3 +3745,383 @@ body {
         grid-template-columns: repeat(2, 1fr);
     }
 }
+
+/* ==================== EXTERNAL CALENDARS STYLES ==================== */
+
+/* External Calendar Section in Sidebar */
+.external-calendar-list {
+    margin-bottom: 2rem;
+}
+
+.external-calendar-list h3 {
+    color: rgba(255, 255, 255, 0.9);
+    font-size: 0.9rem;
+    font-weight: 600;
+    margin-bottom: 1rem;
+    text-transform: uppercase;
+    letter-spacing: 0.5px;
+    padding-left: 0.5rem;
+}
+
+.external-calendar-items {
+    list-style: none;
+    margin: 0;
+    padding: 0;
+}
+
+.external-calendar-item {
+    margin-bottom: 0.5rem;
+}
+
+.external-calendar-info {
+    display: flex;
+    align-items: center;
+    gap: 0.75rem;
+    padding: 0.75rem;
+    border-radius: 8px;
+    transition: all 0.2s ease;
+    cursor: pointer;
+    background: rgba(255, 255, 255, 0.05);
+    border: 1px solid rgba(255, 255, 255, 0.1);
+}
+
+.external-calendar-info:hover {
+    background: rgba(255, 255, 255, 0.1);
+    border-color: rgba(255, 255, 255, 0.2);
+    transform: translateX(2px);
+}
+
+.external-calendar-info input[type="checkbox"] {
+    width: 16px;
+    height: 16px;
+    accent-color: rgba(255, 255, 255, 0.8);
+    cursor: pointer;
+}
+
+.external-calendar-color {
+    width: 12px;
+    height: 12px;
+    border-radius: 50%;
+    border: 1px solid rgba(255, 255, 255, 0.3);
+    flex-shrink: 0;
+}
+
+.external-calendar-name {
+    color: rgba(255, 255, 255, 0.9);
+    font-size: 0.85rem;
+    font-weight: 500;
+    flex: 1;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
+}
+
+.external-calendar-actions {
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+    flex-shrink: 0;
+}
+
+.last-updated {
+    font-size: 0.7rem;
+    color: rgba(255, 255, 255, 0.6);
+    opacity: 0.8;
+}
+
+.external-calendar-refresh-btn {
+    background: none;
+    border: none;
+    color: rgba(255, 255, 255, 0.7);
+    cursor: pointer;
+    font-size: 0.8rem;
+    padding: 2px 4px;
+    border-radius: 3px;
+    transition: all 0.2s ease;
+    line-height: 1;
+}
+
+.external-calendar-refresh-btn:hover {
+    color: rgba(255, 255, 255, 0.9);
+    background: rgba(255, 255, 255, 0.1);
+    transform: rotate(180deg);
+}
+
+.external-calendar-indicator {
+    font-size: 0.8rem;
+    opacity: 0.7;
+    flex-shrink: 0;
+}
+
+/* CalDAV Calendar Styles */
+.calendar-info {
+    display: flex;
+    align-items: center;
+    gap: 0.75rem;
+    padding: 0.75rem;
+    border-radius: 8px;
+    transition: all 0.2s ease;
+    cursor: pointer;
+}
+
+.calendar-info:hover {
+    background: rgba(255, 255, 255, 0.1);
+    transform: translateX(2px);
+}
+
+.calendar-info input[type="checkbox"] {
+    width: 16px;
+    height: 16px;
+    accent-color: rgba(255, 255, 255, 0.8);
+    cursor: pointer;
+}
+
+/* Create External Calendar Button */
+.create-external-calendar-button {
+    background: rgba(255, 255, 255, 0.15);
+    border: 1px solid rgba(255, 255, 255, 0.25);
+    color: rgba(255, 255, 255, 0.9);
+    padding: 0.75rem 1rem;
+    border-radius: 8px;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    margin-bottom: 1rem;
+    font-size: 0.85rem;
+    font-weight: 500;
+    backdrop-filter: blur(10px);
+    width: 100%;
+    position: relative;
+}
+
+.create-external-calendar-button::before {
+    content: "";
+    position: absolute;
+    left: 1rem;
+    font-size: 0.8rem;
+    opacity: 0.8;
+}
+
+.create-external-calendar-button {
+    padding-left: 2.5rem;
+}
+
+.create-external-calendar-button:hover {
+    background: rgba(255, 255, 255, 0.25);
+    border-color: rgba(255, 255, 255, 0.4);
+    transform: translateY(-1px);
+}
+
+.create-external-calendar-button:active {
+    transform: translateY(0);
+}
+
+/* External Calendar Modal */
+.external-calendar-modal {
+    background: white;
+    border-radius: 12px;
+    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
+    max-width: 500px;
+    width: 100%;
+    max-height: 90vh;
+    overflow-y: auto;
+    animation: modalSlideIn 0.3s ease;
+}
+
+.external-calendar-modal .modal-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    padding: 2rem 2rem 1rem;
+    border-bottom: 1px solid #e9ecef;
+}
+
+.external-calendar-modal .modal-header h3 {
+    margin: 0;
+    color: #495057;
+    font-size: 1.5rem;
+    font-weight: 600;
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+}
+
+.external-calendar-modal .modal-header h3::before {
+    content: "📅";
+    font-size: 1.2rem;
+    opacity: 0.8;
+}
+
+.external-calendar-modal .modal-close {
+    background: none;
+    border: none;
+    font-size: 1.5rem;
+    color: #6c757d;
+    cursor: pointer;
+    padding: 0.5rem;
+    border-radius: 50%;
+    width: 2.5rem;
+    height: 2.5rem;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    transition: all 0.2s ease;
+}
+
+.external-calendar-modal .modal-close:hover {
+    background: #f8f9fa;
+    color: #495057;
+}
+
+.external-calendar-modal .modal-body {
+    padding: 1.5rem 2rem 2rem;
+}
+
+.external-calendar-modal .form-group {
+    margin-bottom: 1.5rem;
+}
+
+.external-calendar-modal .form-group label {
+    display: block;
+    margin-bottom: 0.5rem;
+    font-weight: 600;
+    color: #495057;
+    font-size: 0.9rem;
+}
+
+.external-calendar-modal .form-group input[type="text"],
+.external-calendar-modal .form-group input[type="url"] {
+    width: 100%;
+    padding: 0.75rem;
+    border: 1px solid #ced4da;
+    border-radius: 8px;
+    font-size: 0.9rem;
+    transition: all 0.2s ease;
+    background: white;
+}
+
+.external-calendar-modal .form-group input[type="text"]:focus,
+.external-calendar-modal .form-group input[type="url"]:focus {
+    outline: none;
+    border-color: var(--primary-color, #667eea);
+    box-shadow: 0 0 0 2px rgba(102, 126, 234, 0.1);
+}
+
+.external-calendar-modal .form-group input[type="color"] {
+    width: 80px;
+    height: 40px;
+    padding: 0;
+    border: 1px solid #ced4da;
+    border-radius: 8px;
+    cursor: pointer;
+    background: none;
+}
+
+.external-calendar-modal .form-help {
+    display: block;
+    margin-top: 0.5rem;
+    font-size: 0.8rem;
+    color: #6c757d;
+    font-style: italic;
+}
+
+.external-calendar-modal .modal-actions {
+    display: flex;
+    gap: 1rem;
+    justify-content: flex-end;
+    padding: 1.5rem 2rem;
+    border-top: 1px solid #e9ecef;
+    background: #f8f9fa;
+    border-radius: 0 0 12px 12px;
+}
+
+.external-calendar-modal .btn {
+    padding: 0.75rem 1.5rem;
+    border-radius: 8px;
+    font-size: 0.9rem;
+    font-weight: 600;
+    cursor: pointer;
+    transition: all 0.2s ease;
+    border: none;
+    min-width: 100px;
+}
+
+.external-calendar-modal .btn-secondary {
+    background: #6c757d;
+    color: white;
+}
+
+.external-calendar-modal .btn-secondary:hover:not(:disabled) {
+    background: #5a6268;
+    transform: translateY(-1px);
+}
+
+.external-calendar-modal .btn-primary {
+    background: var(--primary-gradient, linear-gradient(135deg, #667eea 0%, #764ba2 100%));
+    color: white;
+}
+
+.external-calendar-modal .btn-primary:hover:not(:disabled) {
+    filter: brightness(1.1);
+    transform: translateY(-1px);
+}
+
+.external-calendar-modal .btn:disabled {
+    opacity: 0.6;
+    cursor: not-allowed;
+}
+
+.external-calendar-modal .error-message {
+    background: #f8d7da;
+    color: #721c24;
+    padding: 0.75rem 1rem;
+    border-radius: 8px;
+    margin-bottom: 1rem;
+    font-size: 0.9rem;
+    border: 1px solid #f5c6cb;
+}
+
+/* External Calendar Events (Visual Distinction) */
+.event[data-external="true"] {
+    position: relative;
+    border-style: dashed !important;
+    opacity: 0.85;
+}
+
+.event[data-external="true"]::before {
+    content: "📅";
+    position: absolute;
+    top: 2px;
+    right: 2px;
+    font-size: 0.7rem;
+    opacity: 0.7;
+    z-index: 1;
+}
+
+/* Mobile Responsive */
+@media (max-width: 768px) {
+    .external-calendar-modal {
+        max-height: 95vh;
+        margin: 1rem;
+        width: calc(100% - 2rem);
+    }
+    
+    .external-calendar-modal .modal-header,
+    .external-calendar-modal .modal-body,
+    .external-calendar-modal .modal-actions {
+        padding-left: 1.5rem;
+        padding-right: 1.5rem;
+    }
+    
+    .external-calendar-info {
+        padding: 0.5rem;
+    }
+    
+    .external-calendar-name {
+        font-size: 0.8rem;
+    }
+    
+    .create-external-calendar-button {
+        font-size: 0.8rem;
+        padding: 0.5rem 1rem 0.5rem 2rem;
+    }
+}