https://github.com/kubernetes/kubernetes/blob/87f9429087d4e31201412548517d36e83abebc8d/pkg/controller/cronjob/cronjob_controller.go#L248-L261

cronjob_controller.go

// from: https://github.com/kubernetes/kubernetes/blob/87f9429087d4e31201412548517d36e83abebc8d/pkg/controller/cronjob/cronjob_controller.go#L248-L261

times, err := getRecentUnmetScheduleTimes(*sj, now)
if err != nil {
	recorder.Eventf(sj, v1.EventTypeWarning, "FailedNeedsStart", "Cannot determine if job needs to be started: %v", err)
	klog.Errorf("Cannot determine if %s needs to be started: %v", nameForLog, err)
	return
}
// TODO: handle multiple unmet start times, from oldest to newest, updating status as needed.
if len(times) == 0 {
	klog.V(4).Infof("No unmet start times for %s", nameForLog)
	return
}
if len(times) > 1 {
	klog.V(4).Infof("Multiple unmet start times for %s so only starting last one", nameForLog)
}