Crontab Reference
Interactive cron expression reference with clickable examples and common patterns
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Cron Syntax
* * * * *
Minute
0-59
* , - /
Hour
0-23
* , - /
Day of Month
1-31
* , - / L W
Month
1-12
* , - /
Day of Week
0-7 (0,7=Sun)
* , - / L #
Test an Expression
Runs daily at 00:00
Frequently Asked Questions
What is a crontab?
A crontab (cron table) is a configuration file that specifies shell commands to run on a schedule in Unix-like operating systems. Each line defines a time pattern and the command to execute.
How do I edit my crontab?
Run "crontab -e" in your terminal to open the crontab editor. Add one cron expression per line followed by the command to run, then save and exit.
What does 0 0 * * * mean in cron?
This cron expression means "at minute 0, hour 0, every day" -- in other words, it runs once daily at midnight (00:00).
How do I run a cron job every 5 minutes?
Use the expression "*/5 * * * *". The */5 in the minute field means every 5 minutes, and the asterisks mean every hour, day, month, and day of week.