Cron Expression Generator — Visual Cron Job Builder & Tester
Build any cron schedule visually and instantly get a plain-English explanation of when it runs. Test expressions, pick from 20+ presets, or enter manually. Supports standard 5-field cron and extended 6-field format for AWS EventBridge, Kubernetes, and more.
📋 Cron Syntax Quick Reference
| Symbol | Meaning | Example |
|---|---|---|
| * | Every value (wildcard) | * in hour = every hour |
| */n | Every n-th value | */5 in minute = every 5 min |
| n | Specific value | 9 in hour = 9 AM |
| n-m | Range | 1-5 in weekday = Mon–Fri |
| n,m | List of values | 0,6 in weekday = Sun & Sat |
| n#m | n-th weekday of month | 1#2 = 2nd Monday |
| L | Last | L in day = last day of month |
| W | Nearest weekday | 15W = nearest weekday to 15th |
What is a Cron Expression?
A cron expression is a time-based scheduling syntax used in Unix-like operating systems to run commands or scripts at specified intervals. It consists of 5 fields (6 for some systems) that define the exact timing: minute, hour, day-of-month, month, day-of-week.
Cron is used everywhere — from Linux server maintenance and database backups to AWS Lambda schedules, Kubernetes CronJobs, GitHub Actions, and CI/CD pipelines. This generator helps you build correct expressions visually without memorizing the syntax.
How to Use the Cron Expression Generator
Choose Your Mode: Use Visual Builder to set each field interactively, Quick Presets for common schedules, or Manual to parse or test any existing cron expression.
See the Plain-English Description: As you type, the tool instantly shows you exactly when the cron job will run in plain English — no guessing required.
Copy & Use: Copy the expression or copy it with a comment for your crontab/config file. The next 5 run times are also displayed for verification.
Frequently Asked Questions
What is a cron expression?
A cron expression is a 5 or 6-field string that defines a schedule: minute (0-59), hour (0-23), day-of-month (1-31), month (1-12), day-of-week (0-7). For example, 0 9 * * 1-5 means every weekday at 9:00 AM.
How do I write a cron job for every 5 minutes?
Use */5 * * * * — the */5 in the minute field means "every 5 minutes". For every 15 minutes: */15 * * * *. For every 30 minutes: */30 * * * *.
What does * (asterisk) mean in cron?
An asterisk (*) means "every possible value". * in the hour field = every hour. * in the month field = every month. */2 means every 2nd value in that field.
How do I run a cron job at midnight daily?
Use 0 0 * * * — minute 0, hour 0 (midnight), every day. For noon: 0 12 * * *. For 9 AM on weekdays only: 0 9 * * 1-5.
What is the difference between 0 and 7 for Sunday in cron?
Both 0 and 7 represent Sunday in cron syntax (on most systems). 1 = Monday, 2 = Tuesday, ... 6 = Saturday. Using 0-6 or 1-7 are both accepted. For portability, use 0 for Sunday.
Does AWS use the same cron format?
AWS EventBridge (CloudWatch Events) uses a slightly different 6-field cron format where the 6th field is the year (optional). AWS also uses ? instead of * when specifying either day-of-month or day-of-week. Use the Manual tab to test AWS-style expressions.