Cron quarterly: the expression, explained, in Next.js / Vercel

The cron expression for “quarterly” is 0 0 1 1,4,7,10 *. This page shows what each field does, the next five times it will fire, the mistake most people make with it, and a working Next.js / Vercel example you can paste.

The expression

0 0 1 1,4,7,10 *
FieldValueMeaning
minute0exactly 0
hour0exactly 0
day of month1exactly 1
month1,4,7,10at 1, 4, 7 and 10
day of week*every day of week

Next five runs (UTC, from now)

  1. 2026-10-01 00:00 UTC
  2. 2027-01-01 00:00 UTC
  3. 2027-04-01 00:00 UTC
  4. 2027-07-01 00:00 UTC
  5. 2027-10-01 00:00 UTC

Mistakes people make with this schedule

  • Writing "*/3" in the month field. Months start at 1, so "*/3" gives January, April, July and October only by luck of the offset; the explicit list is clearer and portable.
  • Assuming the server clock is your clock. Cron runs in the machine’s timezone unless the runtime says otherwise; the examples here are UTC.
  • No lock around a job that might overlap itself, and no alert when it silently stops. That second one is what Supercrontab is for.

Run it in your stack

// vercel.json
{
  "crons": [
    { "path": "/api/cron/run", "schedule": "0 0 1 1,4,7,10 *" }
  ]
}

Vercel crons run in UTC and, on the Hobby plan, at most once a day. For anything more frequent call the route from Supercrontab.

Questions

Does 0 0 1 1,4,7,10 * run in my local time?

Only if the scheduler is configured for it. crontab uses the system timezone; Vercel and GitHub Actions always use UTC; Laravel and node-cron take a timezone option. In Supercrontab the timezone is a field on the job.

What if the previous run is still going?

Classic cron starts the next run anyway. Add a lock (flock on Linux, withoutOverlapping() in Laravel) or let Supercrontab skip the tick while the previous request is open.

Is there a shorter way to write this?

No. The five-field form is the shortest portable version.