Crontab Explainer

The Crontab Explainer takes the cryptic five-field cron syntax that schedules jobs on Linux and Unix systems and rewrites it as a sentence you can actually read.

Cron is everywhere — backups, log rotation, deployment hooks, container schedulers — but its terse format makes it dangerously easy to misread a schedule and run a job at the wrong time.

Paste an expression here and the tool immediately tells you when it fires, along with a clear breakdown of each individual field.

It understands the full standard grammar: the wildcard asterisk for "every", single values, comma-separated lists such as 0,30, ranges like 9-17, and step values such as */15 or 10-30/5.

Month and weekday fields accept the friendly three-letter names too, so MON-FRI and JAN are parsed exactly as a real cron daemon would parse them, with Sunday accepted as either 0 or 7.

Common shortcuts including @daily, @hourly, @weekly, @monthly and @yearly are expanded to their equivalent expressions before being explained.

Invalid expressions get a calm, specific error pointing at the offending field rather than a silent wrong answer, which helps you catch mistakes before they reach production.

Everything runs locally in your browser, so your schedules never leave your machine and the tool works offline.