daily job next logic failed to consider 1 midnight attime (#635)

job.go

@@ -622,12 +622,7 @@ type dailyJob struct {
 }
 
 func (d dailyJob) next(lastRun time.Time) time.Time {
-	next := d.nextDay(lastRun)
-	if !next.IsZero() {
-		return next
-	}
-	startNextDay := time.Date(lastRun.Year(), lastRun.Month(), lastRun.Day()+int(d.interval), 0, 0, 0, lastRun.Nanosecond(), lastRun.Location())
-	return d.nextDay(startNextDay)
+	return d.nextDay(lastRun)
 }
 
 func (d dailyJob) nextDay(lastRun time.Time) time.Time {
@@ -643,6 +638,18 @@ func (d dailyJob) nextDay(lastRun time.Time) time.Time {
 			return atDate
 		}
 	}
+	startNextDay := time.Date(lastRun.Year(), lastRun.Month(), lastRun.Day()+int(d.interval), 0, 0, 0, lastRun.Nanosecond(), lastRun.Location())
+	for _, at := range d.atTimes {
+		// sub the at time hour/min/sec onto the lastRun's values
+		// to use in checks to see if we've got our next run time
+		atDate := time.Date(startNextDay.Year(), startNextDay.Month(), startNextDay.Day(), at.Hour(), at.Minute(), at.Second(), startNextDay.Nanosecond(), startNextDay.Location())
+
+		if !atDate.Before(startNextDay) {
+			// now that we're looking at the next day, it's ok to consider
+			// the same at time that was last run
+			return atDate
+		}
+	}
 	return time.Time{}
 }
 

job_test.go

@@ -50,6 +50,16 @@ func TestDailyJob_next(t *testing.T) {
 		expectedNextRun           time.Time
 		expectedDurationToNextRun time.Duration
 	}{
+		{
+			"daily at midnight",
+			1,
+			[]time.Time{
+				time.Date(0, 0, 0, 0, 0, 0, 0, time.UTC),
+			},
+			time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC),
+			time.Date(2000, 1, 2, 0, 0, 0, 0, time.UTC),
+			24 * time.Hour,
+		},
 		{
 			"daily multiple at times",
 			1,