widget refresh enhancements

ios/TimetableWidgetExtension/TimetableDayView.swift

@@ -100,13 +100,13 @@ struct TimetableDayView: View {
 
     private func header(data: WidgetTimetableData) -> some View {
         HStack(spacing: 4) {
-            Text(dayLabel(for: data.anchorDate))
+            Text(dayLabel(for: data.anchorDate, relativeTo: entry.date))
                 .font(.system(size: 13, weight: .semibold))
                 .foregroundStyle(palette.textPrimary)
                 .lineLimit(1)
                 .minimumScaleFactor(0.7)
             Spacer(minLength: 4)
-            Text("Stand: \(freshnessLabel(for: data.fetchedAt))")
+            Text("Stand: \(freshnessLabel(for: data.fetchedAt, relativeTo: entry.date))")
                 .font(.system(size: 9))
                 .foregroundStyle(palette.textSecondary)
                 .lineLimit(1)
@@ -383,6 +383,7 @@ struct TimeGridView: View {
         case .irregular: return Color(red: 143/255.0, green: 25/255.0, blue: 179/255.0)
         case .teacherChanged: return Color(red: 41/255.0, green: 99/255.0, blue: 155/255.0)
         case .event: return Color(red: 239/255.0, green: 108/255.0, blue: 0/255.0)
+        case .duty: return Color(red: 0/255.0, green: 121/255.0, blue: 107/255.0)
         }
     }
 }
@@ -400,9 +401,31 @@ func periodBoundaries(_ periods: [WidgetPeriod]) -> [Int] {
     return result.sorted()
 }
 
-func dayLabel(for date: Date) -> String {
+/// Fixed-locale formatters cached once — DateFormatter setup is the
+/// expensive part and the multi-entry timelines render up to ~8 entries per
+/// reload. Only touched from WidgetKit's archival rendering, so the shared
+/// instances are safe.
+enum WidgetDateFormatters {
+    static let shortDate = make("dd.MM.")
+    static let weekdayShort = make("EE")
+    static let weekdayDate = make("EEEE · dd.MM.")
+    static let time = make("HH:mm")
+    static let dateTime = make("dd.MM. HH:mm")
+
+    private static func make(_ format: String) -> DateFormatter {
+        let f = DateFormatter()
+        f.locale = Locale(identifier: "de_DE")
+        f.dateFormat = format
+        return f
+    }
+}
+
+/// `now` is the timeline entry's date, not `Date()`: WidgetKit archives
+/// entries ahead of time, so wall-clock reads would be wrong for every
+/// entry after the first.
+func dayLabel(for date: Date, relativeTo now: Date) -> String {
     let cal = Calendar.current
-    let today = cal.startOfDay(for: Date())
+    let today = cal.startOfDay(for: now)
     let anchor = cal.startOfDay(for: date)
     if anchor == today {
         return "Heute · \(shortDate(date))"
@@ -410,35 +433,23 @@ func dayLabel(for date: Date) -> String {
     if let tomorrow = cal.date(byAdding: .day, value: 1, to: today), anchor == tomorrow {
         return "Morgen · \(shortDate(date))"
     }
-    let formatter = DateFormatter()
-    formatter.locale = Locale(identifier: "de_DE")
-    formatter.dateFormat = "EEEE · dd.MM."
-    return formatter.string(from: date)
+    return WidgetDateFormatters.weekdayDate.string(from: date)
 }
 
 func shortDate(_ date: Date) -> String {
-    let f = DateFormatter()
-    f.locale = Locale(identifier: "de_DE")
-    f.dateFormat = "dd.MM."
-    return f.string(from: date)
+    WidgetDateFormatters.shortDate.string(from: date)
 }
 
-func freshnessLabel(for fetchedAt: Date) -> String {
+func freshnessLabel(for fetchedAt: Date, relativeTo now: Date) -> String {
     let cal = Calendar.current
-    let today = cal.startOfDay(for: Date())
+    let today = cal.startOfDay(for: now)
     let fetchedDay = cal.startOfDay(for: fetchedAt)
-    let timeFmt = DateFormatter()
-    timeFmt.locale = Locale(identifier: "de_DE")
-    timeFmt.dateFormat = "HH:mm"
     if fetchedDay == today {
-        return timeFmt.string(from: fetchedAt)
+        return WidgetDateFormatters.time.string(from: fetchedAt)
     }
     if let yesterday = cal.date(byAdding: .day, value: -1, to: today),
        fetchedDay == yesterday {
-        return "gestern \(timeFmt.string(from: fetchedAt))"
+        return "gestern \(WidgetDateFormatters.time.string(from: fetchedAt))"
     }
-    let dateTimeFmt = DateFormatter()
-    dateTimeFmt.locale = Locale(identifier: "de_DE")
-    dateTimeFmt.dateFormat = "dd.MM. HH:mm"
-    return dateTimeFmt.string(from: fetchedAt)
+    return WidgetDateFormatters.dateTime.string(from: fetchedAt)
 }