Build cron expressions visually. See the schedule in plain English.
Cron is a time-based job scheduler found in Unix-like systems. A cron expression is a string of five fields — minute hour day-of-month month day-of-week — that defines when a task should run. The asterisk * means "every," a number means "at exactly," and special characters like */5 (every 5th), 1-5 (range), and 1,15 (list) add flexibility.
Cron is used for scheduled backups, log rotation, report generation, cache clearing, email digests, and deployment pipelines. Cloud platforms like AWS (CloudWatch Events), Google Cloud Scheduler, and GitHub Actions all use cron syntax. Even Kubernetes CronJobs use the same format.
Common mistakes include confusing day-of-week numbering (0=Sunday in most systems), forgetting that both day-of-month and day-of-week can trigger a run (they're OR'd, not AND'd in standard cron), and accidentally scheduling intensive tasks every minute. This tool shows you exactly when your expression will fire next, so you can verify before deploying.
This tool in other languages:
Français:
Constructeur d'expressions cron
Español:
Constructor de expresiones cron
Deutsch:
Cron-Ausdruck-Generator
Português:
Construtor de expressões cron
日本語:
Cron式ビルダー
中文:
Cron 表达式生成器
한국어:
Cron 표현식 빌더
العربية:
منشئ تعبيرات Cron
Use the five control panels (Minute, Hour, Day of Month, Month, Day of Week) to pick values. The cron expression updates live, and a plain-English description tells you exactly when it will run (e.g. "Every day at 9:00 AM"). Click any preset button for common schedules.
Five fields: minute (0-59), hour (0-23), day of month (1-31), month (1-12), day of week (0-6, Sunday=0). An asterisk (*) means "any value". A slash (*/5) means "every 5 units". Commas list multiple values, hyphens define ranges.
Use the expression */5 * * * *. Click the preset Every 5 min to build it automatically. This runs at minute 0, 5, 10, 15, etc. of every hour.
Standard Unix cron has 5 fields. AWS EventBridge and Quartz (Spring Scheduler) use 6 or 7 fields — they add seconds and/or a year field. Also, AWS uses ? (not *) in one of day-of-month or day-of-week. This tool generates standard 5-field Unix cron, compatible with most cron daemons and libraries.
Set day of week to 1-5 (Monday-Friday). For weekdays at 9 AM: 0 9 * * 1-5. Click the Weekdays 9am preset to build it instantly.
Common issues: the cron daemon uses a different timezone than you expect (often UTC), the job's environment has different PATH or variables than your shell, or the command fails silently. Use the "Next 5 runs" preview in this tool to sanity-check your schedule before deploying.