Cron Expression Explainer

About this calculator

A cron expression schedules recurring jobs on Unix-like systems using five space-separated fields — minute, hour, day-of-month, month, and day-of-week — each of which can be a specific number, a range, a comma list, an asterisk for “every,” or a step value like */15. Reading these correctly is easy to get wrong: 0 0 1 * * means midnight on the first of every month, not every hour, and mixing up field order is a common source of scheduling bugs.

Sysadmins, DevOps engineers, and backend developers rely on cron and cron-compatible schedulers (including Kubernetes CronJobs and many CI/CD pipelines) to automate backups, report generation, and maintenance scripts, and use plain-English explanations like this one to sanity-check an expression before deploying it.