Free tools · no login

◷ Cron expression explainer

The cron expression 0 */5 * * * means: at 00:00, 05:00, 10:00, 15:00 and 20:00, every day. In UTC its next runs are Tue 2026-10-13 00:00 and Tue 2026-10-13 05:00. A heartbeat monitor with a 30-minute grace period, pinged at the end of each run, alerts you when the job stops running or fails silently.

Paste a 5-field cron expression. Get what it means in plain English, when it runs next, and what could go wrong. Nothing is sent anywhere; it runs on our server in a few milliseconds.

Try: */5 * * * * (every 5 minutes) · 0 9 * * 1-5 (weekdays 09:00) · 0 0 1 * * (monthly) · 30 2 * * 0 (Sundays 02:30) · 0 9 1-7 * 1 (the OR trap) · @daily (macro)
0 */5 * * *
At 00:00, 05:00, 10:00, 15:00 and 20:00, every day.
minutehourday of monthmonthday of week
0*/5***
00, 5, 10, 15, 2031 values1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 120, 1, 2, 3, 4, 5, 6

Next 10 runs · UTC

  1. Tue 2026-10-13 00:00 UTC (+00:00) · in 3h 52m
  2. Tue 2026-10-13 05:00 UTC (+00:00) · in 8h 52m
  3. Tue 2026-10-13 10:00 UTC (+00:00) · in 13h 52m
  4. Tue 2026-10-13 15:00 UTC (+00:00) · in 18h 52m
  5. Tue 2026-10-13 20:00 UTC (+00:00) · in 23h 52m
  6. Wed 2026-10-14 00:00 UTC (+00:00) · in 1d 3h
  7. Wed 2026-10-14 05:00 UTC (+00:00) · in 1d 8h
  8. Wed 2026-10-14 10:00 UTC (+00:00) · in 1d 13h
  9. Wed 2026-10-14 15:00 UTC (+00:00) · in 1d 18h
  10. Wed 2026-10-14 20:00 UTC (+00:00) · in 1d 23h

Times are UTC, which is what most cloud servers and GitHub Actions use. Set a timezone above to see local times.

Watch out

'*/5' does not divide evenly into 24 hours: it runs at 0, 5, 10, 15 … 20 and then restarts at 0, so the gap across the day boundary is 4 hours, not 5.
Always true for crontab: it runs in the server's timezone (check with date), with a minimal PATH, and % must be escaped as \%.
Full guide with systemd, Kubernetes and GitHub Actions examples: Every 5 hours

Monitor this job

cron never tells you when a job stops running. Add a heartbeat ping after the command: Vigil expects it on this schedule and alerts you if it doesn't arrive within the grace period (we'd suggest 30 minutes here).

crontab -e
0 */5 * * * /usr/local/bin/my-job.sh && curl -fsS -m 10 --retry 3 -o /dev/null https://puzaricloud.in/ping/<your-token>
Report start, finish and exit code (catches failures and hangs, not just silence)
0 */5 * * * curl -fsS -m 10 -o /dev/null https://puzaricloud.in/ping/<your-token>/start; /usr/local/bin/my-job.sh; curl -fsS -m 10 --retry 3 -o /dev/null https://puzaricloud.in/ping/<your-token>/$?

Replace /usr/local/bin/my-job.sh with your command and <your-token> with the token Vigil gives you. && means the ping only goes out when the job succeeded.

Watch this schedule — get alerted if it doesn't run

Link to this result:
How Vigil can watch this for you

Know the moment a cron job doesn't run

Paste the same expression into a Vigil heartbeat. Vigil works out when each run is due in your timezone, waits the grace period, then alerts you if the ping never came, if the job reported a failure, or if it started and never finished.

Monitor a cron job free
Free plan, no card. Alerts on email, Telegram, Slack, Discord, Teams or any webhook.
More free tools:
◔ SLA & uptime calculator◇ DNS & email auth check⇄ HTTP request tester All tools →