Drying out

frontend/src/utils/time.ts

@@ -62,6 +62,45 @@ export function formatElapsedTime(utcTimestamp: string): string {
   return `${mins}m`;
 }
 
+/**
+ * Format a Date or ISO string to a human-readable datetime string (YYYY-MM-DD HH:mm)
+ * @param date - Date object or ISO string
+ * @returns formatted datetime string
+ */
+export function formatDateTime(date: Date | string): string {
+  const d = typeof date === 'string' ? new Date(date) : date;
+  return d.toLocaleString('sv-SE', {
+    year: 'numeric',
+    month: '2-digit',
+    day: '2-digit',
+    hour: '2-digit',
+    minute: '2-digit',
+    hour12: false
+  }).replace(',', ' ');
+}
+
+/**
+ * Convert a datetime-local input value to an ISO UTC string
+ * @param inputValue - datetime-local string (YYYY-MM-DDTHH:mm)
+ * @returns ISO UTC string
+ */
+export function toUTCFromLocalInput(inputValue: string): string {
+  const d = new Date(inputValue);
+  return d.toISOString();
+}
+
+/**
+ * Calculate duration in minutes between two dates or ISO strings
+ * @param start - Start date object or ISO string
+ * @param end - End date object or ISO string
+ * @returns duration in minutes
+ */
+export function getDurationMinutes(start: Date | string, end: Date | string): number {
+  const startDate = typeof start === 'string' ? new Date(start) : start;
+  const endDate = typeof end === 'string' ? new Date(end) : end;
+  return Math.round((endDate.getTime() - startDate.getTime()) / 60000);
+}
+
 /**
  * Clamp a date to day boundaries (start or end of day)
  * @param date - Date to clamp