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◷ Cron expression explainer

The cron expression 0 9 1-7 * 1 means: at 09:00, on days 1 through 7 of the month, and also Monday (cron runs when either day field matches). In UTC its next runs are Mon 2026-10-19 09:00 and Mon 2026-10-26 09:00. 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 9 1-7 * 1
At 09:00, on days 1 through 7 of the month, and also Monday (cron runs when either day field matches).
minutehourday of monthmonthday of week
091-7*1
091, 2, 3, 4, 5, 6, 71, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 121

Next 10 runs · UTC

  1. Mon 2026-10-19 09:00 UTC (+00:00) · in 6d 12h
  2. Mon 2026-10-26 09:00 UTC (+00:00) · in 13d 12h
  3. Sun 2026-11-01 09:00 UTC (+00:00) · in 19d 12h
  4. Mon 2026-11-02 09:00 UTC (+00:00) · in 20d 12h
  5. Tue 2026-11-03 09:00 UTC (+00:00) · in 21d 12h
  6. Wed 2026-11-04 09:00 UTC (+00:00) · in 22d 12h
  7. Thu 2026-11-05 09:00 UTC (+00:00) · in 23d 12h
  8. Fri 2026-11-06 09:00 UTC (+00:00) · in 24d 12h
  9. Sat 2026-11-07 09:00 UTC (+00:00) · in 25d 12h
  10. Mon 2026-11-09 09:00 UTC (+00:00) · in 27d 12h

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

Watch out

Both day-of-month and day-of-week are set, so cron uses OR: it runs on the listed days of the month AND on the listed weekdays. '0 9 1-7 * 1' is not 'first Monday'; it runs on days 1-7 plus every Monday. Use a guard in the command instead (see /cron/first-monday-of-month).
Always true for crontab: it runs in the server's timezone (check with date), with a minimal PATH, and % must be escaped as \%.

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 9 1-7 * 1 /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 9 1-7 * 1 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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