Cron every 2 hours at :15: the expression, explained, in Next.js / Vercel

The cron expression for “every 2 hours at :15” is 15 */2 * * *. 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

15 */2 * * *
FieldValueMeaning
minute15exactly 15
hour*/2every 2 hours, starting at 0
day of month*every day of month
month*every month
day of week*every day of week

Next five runs (UTC, from now)

  1. 2026-09-18 00:15 UTC
  2. 2026-09-18 02:15 UTC
  3. 2026-09-18 04:15 UTC
  4. 2026-09-18 06:15 UTC
  5. 2026-09-18 08:15 UTC

Mistakes people make with this schedule

  • Using "* */2 * * *" for every 2 hours. That runs every minute of every 2th hour. The minute field must be the fixed number 15.
  • 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": "15 */2 * * *" }
  ]
}

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 15 */2 * * * 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.