Fix time duration and visuals

frontend/src/utils/time.ts

@@ -13,7 +13,6 @@ export function formatMinutesAfter(minutes: number | null, reference: string = "
 
   const [refHours, refMinutes] = reference.split(":").map(Number);
   const totalRefMinutes = refHours * 60 + refMinutes;
-
   const targetMinutes = totalRefMinutes + minutes;
   // Handle wrap around midnight
   const normalizedMinutes = ((targetMinutes % 1440) + 1440) % 1440;
@@ -34,26 +33,23 @@ export function toLocalDatetimeInputValue(date: Date): string {
   return localDate.toISOString().slice(0, 16);
 }
 
-/**
- * Format elapsed time in human-readable format
- * @param startTime - start time as ISO string or Date
- * @returns formatted string like "2h 35m" or "just now"
- */
-export function formatElapsedTime(startTime: string | Date): string {
-  const start = typeof startTime === "string" ? new Date(startTime) : startTime;
+export function formatElapsedTime(utcTimestamp: string): string {
+  let isoString = utcTimestamp;
+  if (utcTimestamp.includes(' ')) {
+    isoString = utcTimestamp.replace(' ', 'T');
+  }
+  if (!isoString.endsWith('Z')) {
+    isoString += 'Z';
+  }
+  const then = new Date(isoString);
   const now = new Date();
-  const diffMs = now.getTime() - start.getTime();
+  const diffMs = now - then;
+  const diffMins = Math.floor(diffMs / 60000);
+  const hours = Math.floor(diffMins / 60);
+  const mins = diffMins % 60;
 
-  if (diffMs < 0) return "just now";
-
-  const totalMinutes = Math.floor(diffMs / 60000);
-  const hours = Math.floor(totalMinutes / 60);
-  const minutes = totalMinutes % 60;
-
-  if (hours === 0 && minutes === 0) return "just now";
-  if (hours === 0) return `${minutes}m`;
-  if (minutes === 0) return `${hours}h`;
-  return `${hours}h ${minutes}m`;
+  if (hours > 0) return `${hours}h ${mins}m`;
+  return `${mins}m`;
 }
 
 /**
@@ -77,6 +73,7 @@ export function clampToDay(date: Date, bound: "start" | "end"): Date {
  * @param timeStr - HH:MM format
  * @param baseDate - base date (defaults to today)
  * @returns Date object
+ * @throws Error if timeStr is invalid
  */
 export function parseTime(timeStr: string, baseDate: Date = new Date()): Date {
   const [hours, minutes] = timeStr.split(":").map(Number);
@@ -85,19 +82,6 @@ export function parseTime(timeStr: string, baseDate: Date = new Date()): Date {
   return result;
 }
 
-/**
- * Format minutes as hours and minutes string
- * @param minutes - total minutes
- * @returns formatted string like "12h 30m"
- */
-export function formatMinutes(minutes: number): string {
-  const hours = Math.floor(minutes / 60);
-  const mins = minutes % 60;
-  if (hours === 0) return `${mins}m`;
-  if (mins === 0) return `${hours}h`;
-  return `${hours}h ${mins}m`;
-}
-
 /**
  * Get date string for N days ago
  * @param days - number of days ago
@@ -115,4 +99,14 @@ export function getDaysAgo(days: number): string {
  */
 export function getToday(): string {
   return new Date().toISOString().split("T")[0];
-}
+}
+
+/**
+ * Convert HH:MM time string to total minutes from start of day
+ * @param timeStr - HH:MM format
+ * @returns total minutes
+ */
+export function timeToMinutes(timeStr: string): number {
+  const [hours, minutes] = timeStr.split(":").map(Number);
+  return hours * 60 + minutes;
+}