Cron Expression Generator

Run a Script Every 4 Hours

Use 0 */4 * * * to trigger your cron job every four hours. See how this expression translates to human-readable text.

Minute Reference

Allowed Values
0-59 allowed values
Operators
*any value
,value list separator
-range of values
/step values

Next 5 Run Dates ()

No upcoming dates

What does 0 */4 * * * mean?

The cron expression 0 */4 * * * translates to On the hour, every 4 hours.

Executing exactly six times daily, the four-hour interval is a favorite for heavy background workers. If you are generating complex PDF reports, performing deep virus scans on uploaded files, or syncing massive data warehouses, this schedule gives the server plenty of breathing room between runs.

Related Schedules

Frequently Asked Questions

Common questions about cron expressions and scheduling.

Why might my 4-hour schedule skip a run?

If your server's timezone observes Daylight Saving Time, a run scheduled exactly during the 'spring forward' clock shift might be entirely skipped.

Can I run it every 4 hours, but only on weekdays?

Yes, simply append 1-5 to the day-of-week field: 0 */4 * * 1-5.

What is a cron expression?

A cron expression is a string of five or six fields separated by spaces that represents a set of times. It is used by the cron daemon to execute scheduled background tasks on Unix-like operating systems.

What does this cron expression mean?

To understand what a specific cron expression means, you can break it down into its five standard fields: Minute, Hour, Day of the Month, Month, and Day of the Week. Using our free cron generator at the top of this page will instantly translate any complex syntax into plain, human-readable English.

What is cron expression?

Cron expression is a standard scheduling language used by servers to automate repetitive tasks. Each field in the expression acts as a time filter, and a scheduled script will only execute when the current system time matches all the filters defined in the string.

What is this cron expression?

If you are asking 'what is this cron expression' about a string you found in a server configuration file, simply paste it into the decoder box above. It will break down the exact minute, hour, day, and month the schedule is configured to run, alongside the next five upcoming execution times.

How to read cron expression?

To read a cron expression, scan it from left to right. The first position is the Minute (0-59), the second is the Hour (0-23), the third is the Day of the Month (1-31), the fourth is the Month (1-12), and the fifth is the Day of the Week (0-6, where 0 is Sunday). An asterisk (*) means 'every'.

What is a cron job?

A cron job is an automated background task scheduled to run at specific intervals on a server. System administrators and developers use cron jobs for routine maintenance tasks like taking database backups, sending out daily email reports, or rotating server log files.

What is a cron job in Linux?

In Linux, a cron job is a script or command executed automatically by the crond daemon at a specified time. It allows Linux users to schedule repetitive system tasks without manual intervention. The schedules are defined inside a hidden configuration file called a crontab.

cPanel how to check cron job running?

To check if a cron job is running in cPanel, log into your cPanel dashboard and navigate to the 'Advanced' section. Click on 'Cron Jobs'. Here you can see a list of all scheduled tasks. To verify they are actually executing successfully, you should append an email address in the 'Cron Email' section so cPanel sends you an output report every time the job runs.

What is cron?

Cron is a time-based job scheduling utility built into Unix-like operating systems. Named after Chronos, the Greek personification of time, it runs silently in the background and wakes up every minute to check if any scheduled commands in the crontab files need to be executed.