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◷ Cron expression explainer

The cron expression 0 0 1 1,7 * means: at 00:00, on the 1st of the month, in January and July. In UTC its next runs are Fri 2027-01-01 00:00 and Thu 2027-07-01 00:00. A heartbeat monitor with a 60-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 0 1 1,7 *
At 00:00, on the 1st of the month, in January and July.
minutehourday of monthmonthday of week
0011,7*
0011, 70, 1, 2, 3, 4, 5, 6

Next 10 runs · UTC

  1. Fri 2027-01-01 00:00 UTC (+00:00) · in 80d 3h
  2. Thu 2027-07-01 00:00 UTC (+00:00) · in 261d 3h
  3. Sat 2028-01-01 00:00 UTC (+00:00) · in 445d 3h
  4. Sat 2028-07-01 00:00 UTC (+00:00) · in 627d 3h
  5. Mon 2029-01-01 00:00 UTC (+00:00) · in 811d 3h
  6. Sun 2029-07-01 00:00 UTC (+00:00) · in 992d 3h
  7. Tue 2030-01-01 00:00 UTC (+00:00) · in 1176d 3h
  8. Mon 2030-07-01 00:00 UTC (+00:00) · in 1357d 3h
  9. Wed 2031-01-01 00:00 UTC (+00:00) · in 1541d 3h
  10. Tue 2031-07-01 00:00 UTC (+00:00) · in 1722d 3h

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

Watch out

✓ No gotchas specific to this expression.

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 6 months

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 60 minutes here).

crontab -e
0 0 1 1,7 * /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 0 1 1,7 * 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
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