The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
0 5 */3 * *
This cron command translates to the following (in Human-Readable format):
“Every 3 days at 5:00 am.”
What is a Cron Job & Crontab?
A cron job is a Linux utility used for scheduling the execution of commands or scripts at a specified time and date. Cron is typically used for system maintenance or administration, such as running backups or log rotation.
A crontab is a file that contains instructions for the cron daemon. The cron daemon is a program that runs in the background and executes tasks at specified times. A crontab file consists of a series of lines, each of which represents a task to be executed. Each line has five fields, separated by spaces or tabs.
Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every 3 days at 5:00 am“:
FUN FACT: Cron jobs can be used to automate just about any task that needs to be performed regularly – so get creative and see what you can come up with!.
You might want to set up a crontab or cron job to run every 3 days at 5:00 am for several reasons, including:
- Sending a daily reminder email to yourself
- Backing up your computer every three days
- Checking for updates to your operating system every three days
- Running a script to delete temporary files every three days
Similar Cron Jobs
You might also want to run a crontab:
- every 10 days
- every 5 days
- every 2 days
- every 9 days
- every 3 days
- every 7 days
- every 1 day at 8:00 pm
- every 10 days at 7:00 pm
FUN FACT: When editing your crontab, it is important to use a text editor that supports Unix-style line endings (LF), as opposed to Windows-style line endings (CRLF)..
In this article, you learned how to set up a cron job that runs every 3 days at 5:00 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.