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

An asterisk (*) in a cron field means "every possible value". For example, * in the minute field means every minute, and * in the month field means every month. You can combine it with a step using */N to mean "every N units" — for example, */5 in the minute field means every 5 minutes.

How do I run a cron job every 5 minutes?

Use the expression "*/5 * * * *". The */5 in the minute field means "every 5 minutes". The remaining asterisks mean every hour, every day, every month, and every day of the week. This results in the job running at :00, :05, :10, :15, etc. of every hour.

What is the difference between @daily and "0 0 * * *"?

@daily is a shorthand alias equivalent to "0 0 * * *", which runs once per day at midnight (00:00). Many cron implementations support these named shortcuts: @hourly (0 * * * *), @daily (0 0 * * *), @weekly (0 0 * * 0), @monthly (0 0 1 * *), and @yearly (0 0 1 1 *).

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Cron Expression Builder & Explainer

Build and explain cron expressions instantly. See next 10 run times, get human-readable descriptions, and generate crontab syntax.

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Cron Expression(5 fields: min hour dom month dow)

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Common Presets

Field Breakdown

minute:00

hour:99

day (month):*every value (*)

month:*every Jan (*)

weekday:1-5every 1 values starting at Mon

Cron Expression Builder — Build & Explain Cron Schedules Instantly

A cron expression is a compact string of five fields — minute, hour, day-of-month, month, and day-of-week — that defines exactly when a recurring task should run. This tool converts any cron expression into plain English (e.g., 0 9 * * 1-5 becomes "At 9:00 AM, Monday through Friday"), shows the next 10 scheduled run times in your local timezone, and provides an interactive visual builder so you can construct schedules without memorizing syntax.

💡

Press ⌘+Enter (Mac) or Ctrl+Enter (Windows) to parse your cron expression instantly without clicking the button.

How it works

Build Cron Expressions in Four Steps

Enter an expression

Type any 5-field cron expression or pick a preset like @daily, @weekly, or a weekday-morning example.

Read the explanation

Get an instant human-readable description: "Every 5 minutes", "At midnight on the 1st of every month", etc.

Verify next run times

Check the next 10 scheduled occurrences in local time to confirm the schedule is exactly what you expect.

Copy and deploy

Click Copy to grab the cron expression and paste it into your crontab file, CI/CD config, or cloud scheduler.

Use cases

When Developers Use Cron Expressions

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Automated Backups

Schedule database or file backups nightly, weekly, or on a custom cadence using a cron job.

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Batch Report Generation

Generate and email reports every morning at 8 AM on weekdays using expressions like 0 8 * * 1-5.

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Data Cleanup Jobs

Run cleanup scripts every Sunday at midnight to purge old logs, temp files, or expired sessions.

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Notification Triggers

Send scheduled push notifications, digest emails, or Slack summaries at precise times.

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CI/CD Pipelines

Trigger nightly builds, integration test runs, or dependency audits using cron schedules in GitHub Actions.

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Monitoring & Health Checks

Ping external services every minute or every 5 minutes to verify uptime and catch outages early.

FAQ

Frequently Asked Questions

1What is a cron expression?

A cron expression is a 5-field schedule string (minute, hour, day-of-month, month, day-of-week) used to trigger recurring tasks. For example, "0 9 * * 1-5" runs a job at 9 AM every weekday.

2What does */5 mean in cron?

*/5 means "every 5 units". In the minute field, */5 runs at :00, :05, :10, :15, and so on. You can use the step syntax in any field — for example, */2 in the hour field means every 2 hours.

3How do I run a job on the last day of the month?

Standard cron does not support "last day of month" directly. A common workaround is to use a script that checks whether tomorrow is the 1st of the next month, or to use an extended cron implementation that supports the L modifier.

4Are @daily and 0 0 * * * the same?

Yes. @daily is a shorthand alias for "0 0 * * *", which runs once at midnight every day. Other aliases include @hourly (0 * * * *), @weekly (0 0 * * 0), @monthly (0 0 1 * *), and @yearly (0 0 1 1 *).

Learn more

Developer Guides

📖Cron Expression Cheat Sheet 📖Cron Job Best Practices 📖Scheduling Tasks in Node.js 📖GitHub Actions Cron Schedules

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