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    Cron Expression Generator

    Build cron expressions visually. Pick presets or customise each field and see a human-readable description instantly.

    Free to use. Runs in your browser.

    Pick schedule fields (minute, hour, day, month, weekday) to generate a valid cron expression, or paste an expression to see a human-readable translation.

    Quick Presets

    Custom Builder

    0-59, *, */n

    0-23, *, */n

    1-31, *

    1-12, *

    0-6 (Sun=0)

    Expression

    * * * * *

    Description

    Every minute

    What Is a Cron Expression?

    A cron expression is a string of five (or six) fields that defines a schedule. Originally built for Unix's cron daemon in the 1970s, the same syntax now powers scheduled tasks in AWS CloudWatch, GitHub Actions, Kubernetes CronJobs, Vercel, and almost every CI/CD platform.

    Think of it as a mini-language for time. Instead of saying "every weekday at 9:30 AM", you write30 9 * * 1-5. Compact, precise, and universally understood by scheduling systems worldwide.

    The tricky part is getting the syntax right, a misplaced asterisk can turn a daily job into one that runs every minute. That's where this generator helps: pick your schedule visually and get a validated expression.

    Cron Field Reference

    FieldAllowed ValuesSpecial CharactersExample
    Minute0-59* , - /*/15 = every 15 minutes
    Hour0-23* , - /9-17 = 9 AM to 5 PM
    Day of Month1-31* , - / L W1,15 = 1st and 15th
    Month1-12 or JAN-DEC* , - /1-6 = January to June
    Day of Week0-6 or SUN-SAT* , - / L #1-5 = Monday to Friday

    What this means for you: The asterisk (*) means "every", the slash (/) means "every Nth", the comma (,) means "and", and the dash (-) means "through". Master those four and you can read any cron expression.

    Common Cron Expressions

    ScheduleExpressionUse Case
    Every minute* * * * *Health checks, real-time monitors
    Every 5 minutes*/5 * * * *API polling, cache refresh
    Every hour0 * * * *Log rotation, metric aggregation
    Daily at midnight0 0 * * *Database backups, report generation
    Daily at 9 AM0 9 * * *Morning digest emails, Slack summaries
    Weekdays at 9 AM0 9 * * 1-5Business-hours-only tasks
    Every Monday at 8 AM0 8 * * 1Weekly reports, sprint reminders
    1st of every month0 0 1 * *Monthly invoicing, billing cycles
    Every 6 hours0 */6 * * *Data syncs, sitemap regeneration
    Quarterly (Jan/Apr/Jul/Oct 1st)0 0 1 1,4,7,10 *Quarterly reviews, compliance reports

    Common Cron Mistakes

    Forgetting Timezone

    Cron expressions don't include timezone information. "0 9 * * *" means 9 AM in whatever timezone the server uses, which might be UTC, not your local time. Always check your platform's timezone setting.

    Day-of-Month vs Day-of-Week Conflict

    Setting both day-of-month and day-of-week creates an OR condition in standard cron (it runs on either match). Some systems treat it as AND. Know your platform's behaviour.

    Running Too Frequently

    * * * * * runs every single minute, 1,440 times per day. Great for testing, terrible for production API calls. Always start with a longer interval and decrease.

    Overlapping Executions

    If your job takes 10 minutes but runs every 5 minutes, you'll have overlapping instances. Use a lock mechanism or ensure your schedule interval exceeds the maximum execution time.

    Related Tools

    Unix Timestamp Converter

    Convert timestamps for your scheduled job logs.

    JSON Formatter

    Format cron job configuration files and API responses.

    Regex Tester

    Test patterns for parsing cron job output and logs.

    Chmod Calculator

    Set correct permissions for your cron script files.

    Hash Generator

    Generate checksums for verifying scheduled backup integrity.

    SQL Formatter

    Format the database queries your cron jobs execute.

    How to use this tool

    1

    Select a preset schedule or enter custom values in the 5 fields

    2

    Read the human-readable description to verify your schedule

    3

    Click Copy to grab the cron expression for your config

    Common uses

    • Scheduling automated database backups at midnight
    • Setting up CI/CD pipeline triggers on specific days
    • Configuring monitoring alerts at regular intervals
    • Automating report generation on the first of each month

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    Frequently Asked Questions

    What is a cron expression?
    A cron expression is a string of five fields (minute, hour, day of month, month, day of week) that defines a recurring schedule. It was created for Unix's cron daemon and is now used by AWS, GitHub Actions, Kubernetes, and most CI/CD platforms.
    What does * mean in a cron expression?
    The asterisk means 'every'. So * in the minute field means every minute, * in the hour field means every hour, and so on.
    What does */5 mean?
    The slash means 'every Nth'. */5 in the minute field means every 5 minutes. */2 in the hour field means every 2 hours.
    What timezone do cron expressions use?
    Cron expressions don't include timezone information. The schedule runs in whatever timezone the server or platform is configured to use, often UTC. Always check your platform's timezone setting.
    How do I schedule a job for weekdays only?
    Use 1-5 in the day-of-week field. For example, 0 9 * * 1-5 runs at 9 AM Monday through Friday.
    What's the difference between 5-field and 6-field cron?
    Standard Unix cron uses 5 fields (minute through day-of-week). Some systems like Quartz add a 6th field for seconds at the beginning. This tool uses the standard 5-field format.
    Can I run a job on the last day of the month?
    Standard cron doesn't have a 'last day' keyword. Some extended implementations support L in the day-of-month field. A common workaround is to use a script that checks if tomorrow is the 1st.
    What does 0 0 * * * mean?
    This runs at midnight every day (minute 0, hour 0). It's one of the most common cron expressions, typically used for daily backups and report generation.
    Can I specify multiple values?
    Yes. Use commas to list multiple values: 0 9,12,17 * * * runs at 9 AM, noon, and 5 PM. Use dashes for ranges: 0 9-17 * * * runs every hour from 9 AM to 5 PM.
    How do I avoid overlapping job executions?
    If your job takes longer than the interval between runs, you'll get overlapping instances. Use a lock file, database lock, or your platform's concurrency settings to prevent this.
    What's the minimum interval for cron?
    One minute (* * * * * runs every minute). For sub-minute scheduling, you need a different mechanism, cron wasn't designed for second-level precision.
    Is my cron expression saved anywhere?
    No. This tool runs entirely in your browser. Copy the expression and paste it into your crontab, CI/CD config, or scheduling service.

    Results are for general informational purposes only and should be checked before use. They are not professional advice. See our Disclaimer and Terms of Service.