The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
0 0 */4 * *
This cron command translates to the following (in Human-Readable format):
“Every 4 days at 12:00 am.”
What is a Cron Job & Crontab?
A cron job is a scheduled task that is typically executed by the server in order to automate certain processes or tasks. For example, a cron job could be set up to automatically backup a database every night at 2am.
To create or edit a cron job, users must first open the crontab file using a text editor. The crontab file contains instructions for the cron daemon, which is the program that actually executes the commands specified in the file. Each line in the crontab file represents a single task or command.
Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every 4 days at 12:00 am“:
FUN FACT: Cron jobs are named after the Greek god of time, Chronos – so now you know where the name comes from!.
You might want to set up a crontab or cron job to run every 4 days at 12:00 am for several reasons, including:
- Checking for updates to a software package and installing them
- Deleting temporary files that are more than 4 days old
- Generating reports based on data that is more than 4 days old
Similar Cron Jobs
You might also want to run a crontab:
- every 8 days
- every 6 days
- every 4 days
- every 5 days
- every 3 days
- every 9 days at 3:00 pm
- every 8 days at 5:00 am
- every 4 days at 5:00 pm
FUN FACT: Each user on a system can have their own crontab, and commands in them will be executed as that user..
In this article, you learned how to set up a cron job that runs every 4 days at 12:00 am. 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.