What is a cron expression?

A cron expression is a string of five fields separated by spaces that defines when a scheduled job should run. The fields represent minute, hour, day of month, month, and day of week. An asterisk (*) means every value for that field.

What does the asterisk (*) mean in a cron expression?

An asterisk means every possible value for that field. For example, * in the hour field means every hour. * in the minute field means every minute.

What is the difference between day of month and day of week?

Day of month selects a specific calendar date (1 to 31). Day of week selects a day by name or number (0 = Sunday, 6 = Saturday). Most cron implementations run a job if either field matches, so combining both can cause unexpected double-triggering.

How accurate are the next run time predictions?

The next run times are calculated from the current moment using the expression fields you have set. They are computed entirely in your browser and are as accurate as your local system clock.

Can I use this expression with any scheduler?

The standard five-field format shown here is supported by UNIX cron, crontab, AWS EventBridge, GitHub Actions, and most job schedulers. Some systems (like Quartz) add a seconds field as the first field, which is not included here.

Cron Builder

Build cron expressions visually. See next run times.

Presets

Minute

Hour

Day (month)

Month

Day (week)

0 0 * * *

Runs at 00:00 every day of month, every day of week, in every month

Next 5 runs

5/10/2026, 12:00:00 AM
5/11/2026, 12:00:00 AM
5/12/2026, 12:00:00 AM
5/13/2026, 12:00:00 AM
5/14/2026, 12:00:00 AM

Your files never leave your device

When to use this

Schedule backups

Build a cron expression for nightly database or file backups.

GitHub Actions

Generate the schedule trigger syntax for GitHub Actions workflows.

AWS EventBridge

Create cron rules for Lambda functions and scheduled tasks.

Free visual cron expression builder

Select values for each cron field using the interactive dropdowns and see the expression string update instantly. A plain-English description explains exactly when the job will run, and the next five execution times are listed below.

Use the presets for common schedules like hourly, daily at midnight, or every Monday morning. Copy the finished expression with one click to paste directly into crontab, GitHub Actions, AWS EventBridge, or any other scheduler.

All calculation happens in your browser. No account needed.

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Go Pro

Free visual cron expression builder

All calculation happens in your browser. No account needed.