Terms of Service

About this tool

This free browser utility explains standard five-field Unix cron expressions and calculates upcoming run times. It runs locally and requires no account. Use it only if you agree to these terms.

Your responsibility

You are responsible for the schedules and commands you enter and for any change you make to a server or job scheduler. Verify a schedule in the environment that will run it before relying on it. Check permissions, paths, environment variables, time zone settings and the behavior of the actual cron daemon. Keep a copy of the original crontab and a way to restore it.

Accuracy and limits

The explanation follows cronie-style Unix crontab semantics. Other cron implementations and job schedulers can differ in their day-field rule, time zone handling, supported names and daylight saving behavior. The explainer supports five fields, not Quartz, Spring or AWS six- and seven-field syntax, and it does not translate systemd timer expressions. It does not inspect a Kubernetes CronJob manifest or apply a manifest's separate time zone field.

Next runs are searched for up to 8 years. A date that never occurs returns no run. The input field is limited to 4,096 characters. Parsing and scheduling run on the browser main thread, so an unusually long expression may briefly delay the page.

Time zones and daylight saving time

Time zone calculations use the browser's IANA time zone data and the zone selected in the page or embedded in the expression with CRON_TZ=. That data and the rules of a particular zone can change. Nonexistent local times at spring-forward are skipped, and a repeated local time at fall-back is listed once at its first occurrence. The UTC column is provided for comparison. Verify daylight saving behavior with the daemon that will run the job.

Privacy

Expressions and settings are processed locally as described in the Privacy Policy. Your original input is not changed.

Availability

The service is provided "as is" and "as available," without a guarantee of accuracy, compatibility or uninterrupted operation. Nothing here limits rights that cannot lawfully be excluded.

Components and changes

This tool uses only built-in browser features and includes no third-party runtime libraries. Features and these terms may change; later use is subject to the terms then shown.