Cron Expression Generator

Build cron expressions visually or paste one to decode. See human-readable description and next run times.

Advanced — 10 runs · Local · Validation on
Schedule Display

What is Cron Expression Generator?

A cron expression generator helps you create and understand cron schedule strings—the five-field format used by Linux crontab, GitHub Actions, Jenkins, and cloud job schedulers. Each field controls when a task runs: minute (0–59), hour (0–23), day of month (1–31), month (1–12), and day of week (0–6). The tool has two modes: Generate builds expressions from dropdowns and presets; Decode explains existing expressions in plain English.

Real-world use cases include scheduling backups, running CI pipelines, sending reports, and triggering data syncs. Instead of memorizing syntax like 0 9 * * 1-5, you select "Weekdays at 9am" and get the correct expression. The next-run-times preview confirms when your job will actually execute, and validation hints flag unsupported values or edge cases.

How to Use Cron Expression Generator

  1. Switch between Generate and Decode tabs depending on whether you're building or interpreting a cron expression.
  2. In Generate mode: select values for minute, hour, day of month, month, and day of week from the dropdowns. Use Custom to enter ranges (e.g. 1-5), steps (e.g. */15), or lists (e.g. 1,15,30).
  3. Click Generate or choose a Common Schedule (e.g. "Every hour", "Daily at midnight", "Weekly Monday 9am").
  4. Review the generated expression, human-readable description, and next 5–20 run times (configurable in Advanced).
  5. In Decode mode: paste an existing cron expression and click Decode to see its meaning and next run times.
  6. Use Advanced to set timezone (Local, UTC, or specific zones) and enable validation hints for unsupported ranges.

Tips & Best Practices

* means "every" for that field; */5 means "every 5 units" (e.g. every 5 minutes). L is valid only in day-of-month for "last day of month." Day-of-week uses 0=Sunday, 6=Saturday. Be aware that some systems (e.g. GitHub Actions) use 6 fields (adding seconds); this tool uses the standard 5-field format. Use the timezone selector when scheduling across regions. Press Ctrl+Enter to run, Ctrl+Shift+C to copy, and Esc to clear.

When to Use This Tool

Use the Cron Expression Generator when configuring crontab, GitHub Actions workflows, Jenkins jobs, or cloud schedulers (AWS EventBridge, Google Cloud Scheduler). It's ideal when you need to verify "what does this cron actually run?" or when building schedules for reports, backups, or CI. For related tasks: use the Unix timestamp converter to convert cron run times to epoch values, or the UUID generator for unique job IDs.

Frequently Asked Questions

What is a cron expression?

A cron expression defines when a task runs. Five fields: minute, hour, day of month, month, day of week. Example: 0 9 * * 1 means every Monday at 9:00 AM.

How do I build a cron expression?

Use the Generate tab: select values for each field or choose a Common Schedule, then click Generate. Use Custom to enter ranges, steps, or lists. The human-readable description explains the schedule in plain English.

Can I decode an existing cron expression?

Yes. Switch to the Decode tab, paste any 5-field cron expression, and click Decode. You'll see the human-readable description, frequency stats, and next run times instantly.

What do * and */5 mean in cron?

* means every value (e.g. every minute). */5 means every 5 units (e.g. every 5 minutes). Steps, ranges (1-5), and lists (1,3,5) are also supported. L is only valid in day-of-month.

Can I see when my cron will run next?

Yes. After generating, the tool shows the next 10 run times (configurable 5–20) based on your selected timezone. Enable validation hints to see warnings about unsupported ranges or invalid values.

Where can I use cron expressions?

Cron is used in Linux crontab, CI/CD (GitHub Actions, Jenkins), cloud schedulers, and job queues. For Unix timestamps, try our Unix timestamp converter.