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Cron Expression Builder

Build, validate, and understand cron expressions - 100% in your browser

Live Preview

Cron Expression

Valid expression

Runs every minute every day

Visual Builder

Minute

0-59

Hour

0-23

Day of Month

1-31

Month

1-12

Day of Week

0-7 (Sun=0,7)

Common Presets

Next Executions

1
Sun, Feb 8
02:15 PM
2
Sun, Feb 8
02:16 PM
3
Sun, Feb 8
02:17 PM
4
Sun, Feb 8
02:18 PM
5
Sun, Feb 8
02:19 PM

Expression Breakdown

Minute*

every minute

Hour*

every hour

Day of Month*

every day

Month*

every month

Day of Week*

every day

Quick Reference

*Any value
,Value list (1,2,3)
-Range (1-5)
/Step (*/5)

How to Use This Cron Builder

1

Select or Build

Choose a preset like "Every 5 minutes" or use the visual builder to configure each field.

2

Verify Schedule

Check the plain English explanation and next 10 execution times to confirm accuracy.

3

Copy & Use

Copy the expression and paste it into your crontab, Kubernetes, GitHub Actions, or scheduler.

What This Builder Does

Visual Field Builder

Configure each cron field (minute, hour, day, month, weekday) with dropdowns and checkboxes—no syntax memorization needed.

Execution Preview

See the next 10 scheduled execution times with exact dates and times in your local timezone.

Plain English Explanation

Every expression is translated into human-readable language like "At 9:00 AM, Monday through Friday".

Real-Time Validation

Instant feedback on syntax errors with clear error messages explaining what went wrong.

Quick Reference: Common Schedules

ScheduleExpressionExplanation
Every minute* * * * *Runs 1,440 times per day
Every 5 minutes*/5 * * * *At 0, 5, 10, 15... minutes
Every hour0 * * * *At the top of every hour
Daily at midnight0 0 * * *At 12:00 AM every day
Daily at 9 AM0 9 * * *At 9:00 AM every day
Weekdays at 9 AM0 9 * * 1-5Mon-Fri at 9:00 AM
Weekly on Sunday0 0 * * 0Sunday at midnight
First of month0 0 1 * *1st day of month at midnight

Troubleshooting Cron Issues

Expression Not Valid

Common syntax errors: minute must be 0-59, hour 0-23, day 1-31, month 1-12, weekday 0-7.

Solution: Check the field ranges and ensure you're using valid special characters (*, /, -, ,).

Job Runs at Wrong Time

Cron uses the server's timezone, not yours. GitHub Actions uses UTC only.

Solution: Convert your desired time to the server's timezone before building the expression. For Kubernetes 1.27+, use spec.timeZone.

Job Runs Too Often / Not Enough

Day-of-month and day-of-week use OR logic when both are specified.

Solution: If you want "first Monday of month", you'll need a script check—cron alone can't express this. Use * in one of the day fields if you only want the other.

Platform-Specific Tips

Linux / crontab

Edit with crontab -e. Use absolute paths. Check logs at /var/log/cron.

0 9 * * * /usr/bin/python3 /home/user/script.py

Kubernetes CronJob

Uses UTC by default. Set spec.timeZone in K8s 1.27+. Consider concurrencyPolicy.

schedule: "0 9 * * 1-5"

GitHub Actions

UTC only. May have delays during high load. Minimum interval: 5 minutes. Inactive repos may have schedules disabled.

cron: '0 9 * * 1-5'

AWS EventBridge

Uses 6 fields with year. Requires ? in day-of-month OR day-of-week. UTC only.

cron(0 9 ? * MON-FRI *)

Frequently Asked Questions

Can I paste an existing cron expression to decode it?

Yes! Paste your expression into the input field at the top. The builder will parse it, show the plain English explanation, display next execution times, and let you modify it with the visual builder.

What timezone does this builder use?

The next execution times are shown in your local browser timezone. However, when you deploy your cron expression, it will use the server's timezone (often UTC for cloud platforms). Adjust accordingly.

Why does my cron job run at the wrong time?

Most cloud platforms (GitHub Actions, AWS) use UTC. Convert your local time to UTC before building the expression. Linux crontab uses the server's local timezone.

Can I create a schedule like 'first Monday of month'?

Standard cron can't express this directly. You'll need '0 0 * * 1' (every Monday) combined with a script that checks if the date is 1-7. Some extended cron implementations support this with special syntax.

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