Cron daily at 03:15: the expression, explained, in GitHub Actions
The cron expression for “daily at 03:15” is 15 3 * * *. This page shows what each field does, the next five times it will fire, the mistake most people make with it, and a working GitHub Actions example you can paste.
The expression
| Field | Value | Meaning |
|---|---|---|
| minute | 15 | exactly 15 |
| hour | 3 | exactly 3 |
| day of month | * | every day of month |
| month | * | every month |
| day of week | * | every day of week |
Next five runs (UTC, from now)
- 2026-09-18 03:15 UTC
- 2026-09-19 03:15 UTC
- 2026-09-20 03:15 UTC
- 2026-09-21 03:15 UTC
- 2026-09-22 03:15 UTC
Mistakes people make with this schedule
- 03:15 in which timezone? A server in UTC fires an hour or two off in Berlin depending on the season. Set the job timezone explicitly.
- 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
# .github/workflows/cron.yml
on:
schedule:
- cron: '15 3 * * *'
jobs:
run:
runs-on: ubuntu-latest
steps:
- run: curl -fsS https://example.com/cron/runScheduled workflows can be delayed by many minutes at busy hours, and are disabled after 60 days of repo inactivity.
Questions
Does 15 3 * * * 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.