No idea what it is doing... very sad

frontend/src/components/stats/SessionList.tsx

@@ -4,7 +4,7 @@ import { useSettings } from '../../hooks/useSettings';
 import { Pagination } from './Pagination';
 import { Edit2, Check, X, Trash2 } from 'lucide-react';
 import type { SleepSessionRead } from '../../types';
-import { formatDateTime, toLocalDatetimeInputValue, getDurationMinutes, formatMinutes, toUTCFromLocalInput } from '../../utils/time';
+import { formatDateTime, toLocalDatetimeInputValue, getDurationMinutes, formatMinutes, toUTCFromLocalInput, parseBackendDateTime } from '../../utils/time';
 
 export function SessionList() {
   const { sessions, isLoading, updateSession, deleteSession, isDeleting } = useSessions();
@@ -57,8 +57,8 @@ export function SessionList() {
 
   const startEditing = (s: SleepSessionRead) => {
     setEditingId(s.id);
-    setEditStart(toLocalDatetimeInputValue(new Date(s.start_time)));
-    setEditEnd(s.end_time ? toLocalDatetimeInputValue(new Date(s.end_time)) : '');
+    setEditStart(toLocalDatetimeInputValue(parseBackendDateTime(s.start_time)));
+    setEditEnd(s.end_time ? toLocalDatetimeInputValue(parseBackendDateTime(s.end_time)) : '');
   };
 
   const handleCancel = () => {
@@ -161,6 +161,6 @@ export function SessionList() {
           onPageChange={setCurrentPage} 
         />
       )}
-    </div>
+    </div >
   );
 }

frontend/src/utils/time.ts

@@ -198,3 +198,15 @@ export function formatMinutes(totalMinutes: number): string {
   }
   return `${mins}m`;
 }
+
+/**
+ * Parses a backend timestamp string into a Date object, 
+ * ensuring it is treated as UTC if no timezone info is present.
+ */
+export function parseBackendDateTime(time: string): Date {
+  if (typeof time === 'string' && !time.endsWith('Z') && !time.includes('+')) {
+    return new Date(time + 'Z');
+  }
+  // If it already has Z or offset, new Date() will handle it correctly.
+  return new Date(time);
+}