$ crongen
Plain-English explanation and next run times. Forgot the syntax — pick a preset.
expression
Cron syntax cheat sheet
| Field | Range | Examples |
|---|---|---|
| minute | 0–59 | 0, */15, 10,40 |
| hour | 0–23 | 3, 9-18, */6 |
| day of month | 1–31 | 1, 1,15 |
| month | 1–12 | *, 6-8 |
| day of week | 0–7 (0 and 7 = Sun) | 1-5, 6,0 |
The gotchas
Day-of-month and day-of-week both set (neither is *) — the job fires when either matches. It's OR, not AND.
Kubernetes CronJob evaluates the schedule in the kube-controller-manager timezone (usually UTC) unless spec.timeZone is set; crontab uses the machine's local time.
Classic cron has no seconds field. 6 fields is Quartz — crontab and CronJob won't accept it.