The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
10 */4 * * *
This cron command translates to the following (in Human-Readable format):
“Every 4 hours at 10 minutes past the hour.”
What is a Cron Job & Crontab?
A cron job is a time-based task that is set to run at a specific time or interval. These jobs are usually used for automating tasks, such as running backups or sending emails. Cron is the name of the program that enables users to schedule these jobs.
A crontab is a table or list of commands that are scheduled to run at specified times. The commands in a crontab file (also called a “cron table”) are normally executed by the cron daemon, which runs in the background and executes these commands automatically.
Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every 4 hours at 10 minutes past the hour“:
FUN FACT: Cron jobs are named after the Greek god Chronos, who represents time itself..
You might want to set up a crontab or cron job to run every 4 hours at 10 minutes past the hour for several reasons, including:
- Running a backup every 4 hours
- Checking for new updates every 4 hours
- Sending out a report every 4 hours
Similar Cron Jobs
You might also want to run a crontab:
- every 9 hours
- every 2 hours
- every 3 hours
- every 8 hours
- every hour between 8:00 am and 9:00 am
- every hour between 11:00 am and 2:00 pm
- every hour between 2:00 am and 3:00 am
FUN FACT: When troubleshooting issues with cron jobs, it can be helpful to run them manually from the command line – this will allow you to see any error messages that might be generated..
In this article, you learned how to set up a cron job that runs every 4 hours at 10 minutes past the hour. Please share this page with friends and colleagues if you find it useful.
If you have any questions, please don’t hesitate to comment below.
If you are looking for cron jobs that run at certain minutes, hours, days, weekdays, or months, or if you are looking for miscellaneous cron jobs, then check out our relevant sections, or visit our crontab cheat sheet for a list of hundreds of popular cron jobs.