-// none. The clock gives the time and the time zone of the schedules.
-func openSchedules(path string, clock func() time.Time) (*Schedules, error) {
+// none. The clock gives the time and the time zone of the schedules, and logger
+// gets one line for each run.
+func openSchedules(path string, clock func() time.Time, logger *log.Logger) (*Schedules, error) {