# Cron expression generator for Next.js & Supabase. In your browser.

Build five-field cron, inspect the next five nominal runs in your zone and export Vercel or pg_cron configuration. No jobs are scheduled — free, no sign-up.

Page: https://saascode.ai/tools/cron-expression-generator

## How to use

1. Choose Vercel Cron or Supabase pg_cron and set five numeric fields or a preset.
2. Choose your IANA display zone. Vercel schedules in UTC; for pg_cron select the actual worker zone.
3. Explain and generate cron. Review the next five times and provider limits before using the configuration in your environment.

## Scope

No deployment, SQL execution or scheduling. Numeric five-field subset; five nominal times within eight years. Vercel UTC is fixed; pg_cron preview assumes the selected worker zone.

## References

- [Vercel syntax and UTC — verified 2026-10-09](https://vercel.com/docs/cron-jobs)
- [Vercel plan limits — verified 2026-10-09](https://vercel.com/docs/cron-jobs/usage-and-pricing)
- [Supabase Cron setup — verified 2026-10-09](https://supabase.com/docs/guides/cron/quickstart)
- [pg_cron timezone and syntax — verified 2026-10-09](https://github.com/citusdata/pg_cron)

## Provider differences — verified 2026-10-09

Sources below document each difference. Review monthly, next due 2026-11-09. Displaying a zone does not change provider configuration.

| Feature | Vercel Cron | Supabase / pg_cron |
| --- | --- | --- |
| Target | HTTP route in vercel.json | SQL registered with cron.schedule |
| Zone | Always UTC | Worker cron.timezone; upstream default GMT |
| Day fields | One day field must be * | Restricted day fields combine with OR |
| Extra syntax | Five numeric fields; no names | Version-dependent extras; not generated here |
| Precision | Hobby daily/per-hour; paid plans per-minute | Database worker timing; long jobs affect delivery |

## Build your SaaS

[Build from SaaSCode Base](https://saascode.ai/free)

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## FAQ

### Is this free, and does my input leave the browser?

Free, no sign-up. Computation, copy and downloads stay in your browser. There is no upload or processing endpoint. Usage analytics include only a fixed tool name and action, never your input or result.

### Does my time zone change Vercel's schedule?

No. Vercel always uses UTC. Your zone changes only displayed dates; the expression is never silently converted. A fixed UTC hour can shift on your local clock at daylight-saving changes.

### How is pg_cron different?

Vercel calls a route with HTTP. pg_cron runs SQL and uses worker cron.timezone, whose upstream default is GMT. Session TimeZone alone does not set the worker zone. Verify your Supabase extension setup and installed version.

### What syntax is supported?

Five numeric fields, *, lists, ranges and positive steps. Vercel rejects names and simultaneous restrictions on day-of-month/day-of-week. pg_cron combines restricted day fields with OR. Version-dependent pg_cron seconds intervals and last-day syntax are outside this workspace's common subset.

### Are these exact runs, and does Hobby accept every expression?

They are nominal instants, not delivery guarantees. Verified 2026-10-09: Hobby is limited to once daily with per-hour precision; Pro and Enterprise support per-minute schedules. Review current provider limits before deploying.

### How are impossible dates and DST handled?

cron-parser uses IANA zone rules and looks for five future occurrences within eight years. Impossible dates or insufficient occurrences produce an error. Confirm local pg_cron behavior against your worker version around gaps and repeated hours.