Improve dashboard health and state recovery

internal/scheduler/cron_test.go

@@ -44,6 +44,18 @@ func TestPreviousWithinCatchUpWindow(t *testing.T) {
 	}
 }
 
+func TestPreviousScheduledUsesJobTimezone(t *testing.T) {
+	now := time.Date(2026, 7, 13, 8, 0, 0, 0, time.UTC)
+	want := time.Date(2026, 7, 13, 0, 0, 0, 0, time.UTC)
+	got, err := PreviousScheduled("0 2 * * *", "Europe/Berlin", now, 24*time.Hour)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !got.Equal(want) {
+		t.Fatalf("previous scheduled = %v, want %v", got, want)
+	}
+}
+
 func TestCronUsesOrForRestrictedMonthDayAndWeekday(t *testing.T) {
 	expr, err := Parse("0 2 1 * 1")
 	if err != nil {

internal/scheduler/scheduler.go

@@ -14,6 +14,21 @@ type Enqueue func(model.Job) error
 type EnqueueMaintenance func(string, string) (model.Run, error)
 type LastRun func(string) time.Time
 
+func PreviousScheduled(spec, timezone string, now time.Time, window time.Duration) (time.Time, error) {
+	expression, err := Parse(spec)
+	if err != nil {
+		return time.Time{}, err
+	}
+	loc := time.Local
+	if timezone != "" {
+		loc, err = time.LoadLocation(timezone)
+		if err != nil {
+			return time.Time{}, err
+		}
+	}
+	return previous(expression, now.In(loc), window).UTC(), nil
+}
+
 type Scheduler struct {
 	config      ConfigProvider
 	enqueue     Enqueue