Understand cron expressions in plain English. See next execution times and build cron schedules. Free developer tool. This tool runs entirely in your browser — no data is sent to any server. It's fast, free, and works on any device.
Cron is Unix's built-in job scheduler, running tasks at specified times using a compact 5-field expression: minute (0-59), hour (0-23), day of month (1-31), month (1-12), and day of week (0-7). Despite its power, cron syntax is notoriously confusing — even experienced sysadmins double-check their expressions. '*/15 * * * *' means every 15 minutes, '0 9 * * 1-5' means 9 AM weekdays, and '0 0 1 * *' means midnight on the first of each month. This parser translates cryptic cron expressions into plain English and shows upcoming execution times, so you can verify your schedule before deploying. It handles standard cron, extended syntax with seconds, and common special characters (@yearly, @daily, @hourly).
The / is a step value. */5 in the minute field means 'every 5 minutes' (0, 5, 10, 15...). You can also use ranges: 1-30/5 means every 5 minutes during the first 30 minutes.
In standard cron, * means 'every value.' The ? (question mark) is used in some implementations (like Quartz scheduler) to mean 'no specific value' in day-of-month or day-of-week fields to avoid conflicts.
Use: 0 9 * * 1-5 (minute=0, hour=9, any day of month, any month, Monday through Friday). Some systems accept MON-FRI instead of 1-5.
Standard system cron uses the server's timezone. Cloud schedulers (AWS EventBridge, GitHub Actions) often default to UTC. Always verify the timezone, especially for international teams. Our Crontab Generator includes timezone notes.
Standard cron's minimum interval is 1 minute. For sub-minute scheduling, use two cron entries offset by 30 seconds, or use a different scheduler like systemd timers, which support arbitrary intervals.