diff --git a/backend/src/handlers/events.rs b/backend/src/handlers/events.rs
index b80c91f..8257131 100644
--- a/backend/src/handlers/events.rs
+++ b/backend/src/handlers/events.rs
@@ -845,7 +845,7 @@ fn parse_event_datetime(
     time_str: &str,
     all_day: bool,
 ) -> Result<chrono::DateTime<chrono::Utc>, String> {
-    use chrono::{Local, NaiveDate, NaiveDateTime, NaiveTime, TimeZone, Utc};
+    use chrono::{NaiveDate, NaiveDateTime, NaiveTime, TimeZone, Utc};
 
     // Parse the date
     let date = NaiveDate::parse_from_str(date_str, "%Y-%m-%d")
@@ -866,11 +866,7 @@ fn parse_event_datetime(
         // Combine date and time
         let datetime = NaiveDateTime::new(date, time);
 
-        // Treat the datetime as local time and convert to UTC
-        let local_datetime = Local.from_local_datetime(&datetime)
-            .single()
-            .ok_or_else(|| "Ambiguous local datetime".to_string())?;
-        
-        Ok(local_datetime.with_timezone(&Utc))
+        // Frontend now sends UTC times, so treat as UTC directly
+        Ok(Utc.from_utc_datetime(&datetime))
     }
 }
diff --git a/backend/src/handlers/series.rs b/backend/src/handlers/series.rs
index ed1d0a8..f1b8584 100644
--- a/backend/src/handlers/series.rs
+++ b/backend/src/handlers/series.rs
@@ -130,13 +130,9 @@ pub async fn create_event_series(
             .and_hms_opt(23, 59, 59)
             .ok_or_else(|| ApiError::BadRequest("Invalid end date".to_string()))?;
 
-        // Convert from local time to UTC
-        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()))?;
+        // Frontend now sends UTC times, so treat as UTC directly
+        let start_local = chrono::Utc.from_utc_datetime(&start_dt);
+        let end_local = chrono::Utc.from_utc_datetime(&end_dt);
         
         (
             start_local.with_timezone(&chrono::Utc),
@@ -171,13 +167,9 @@ pub async fn create_event_series(
             start_date.and_time(end_time)
         };
 
-        // Convert from local time to UTC
-        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()))?;
+        // Frontend now sends UTC times, so treat as UTC directly
+        let start_local = chrono::Utc.from_utc_datetime(&start_dt);
+        let end_local = chrono::Utc.from_utc_datetime(&end_dt);
         
         (
             start_local.with_timezone(&chrono::Utc),
@@ -456,13 +448,9 @@ pub async fn update_event_series(
             (chrono::Utc.from_utc_datetime(&start_dt) + original_duration).naive_utc()
         };
 
-        // Convert from local time to UTC
-        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()))?;
+        // Frontend now sends UTC times, so treat as UTC directly
+        let start_local = chrono::Utc.from_utc_datetime(&start_dt);
+        let end_local = chrono::Utc.from_utc_datetime(&end_dt);
         
         (
             start_local.with_timezone(&chrono::Utc),
diff --git a/frontend/src/app.rs b/frontend/src/app.rs
index e003453..edbf1f2 100644
--- a/frontend/src/app.rs
+++ b/frontend/src/app.rs
@@ -761,11 +761,30 @@ pub fn App() -> Html {
                             String::new()
                         };
 
-                        // Send local time directly to backend (backend will handle UTC conversion)
-                        let start_date = new_start.format("%Y-%m-%d").to_string();
-                        let start_time = new_start.format("%H:%M").to_string();
-                        let end_date = new_end.format("%Y-%m-%d").to_string();
-                        let end_time = new_end.format("%H:%M").to_string();
+                        // Convert local naive datetime to UTC before sending to backend
+                        use chrono::TimeZone;
+                        let local_tz = chrono::Local;
+                        
+                        let start_utc = local_tz.from_local_datetime(&new_start)
+                            .single()
+                            .unwrap_or_else(|| {
+                                // Fallback for ambiguous times (DST transitions)
+                                local_tz.from_local_datetime(&new_start).earliest().unwrap()
+                            })
+                            .with_timezone(&chrono::Utc);
+                            
+                        let end_utc = local_tz.from_local_datetime(&new_end)
+                            .single()
+                            .unwrap_or_else(|| {
+                                // Fallback for ambiguous times (DST transitions)
+                                local_tz.from_local_datetime(&new_end).earliest().unwrap()
+                            })
+                            .with_timezone(&chrono::Utc);
+
+                        let start_date = start_utc.format("%Y-%m-%d").to_string();
+                        let start_time = start_utc.format("%H:%M").to_string();
+                        let end_date = end_utc.format("%Y-%m-%d").to_string();
+                        let end_time = end_utc.format("%H:%M").to_string();
 
                         // Convert existing event data to string formats for the API
                         let status_str = match original_event.status {