The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
30 13 */3 * *
This cron command translates to the following (in Human-Readable format):
“Every 3 days at 1:30 pm.”
What is a Cron Job & Crontab?
A cron job is a task that is scheduled to run at a specific time or interval. Cron jobs are commonly used to automate system maintenance or administration tasks, such as running backups or sending emails.
Crontab is a file that contains instructions for the cron daemon, which is a program that executes commands at specified intervals. Crontab files are typically edited with the crontab command, which allows users to create, edit, and delete their own crontab files.
Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every 3 days at 1:30 pm“:
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..
You might want to set up a crontab or cron job to run every 3 days at 1:30 pm for several reasons, including:
- A daily backup that needs to run every 3 days
- A cron job that emails a report every 3 days
- Running a script every 3 days that cleans up temporary files
Similar Cron Jobs
You might also want to run a crontab:
- every 4 days
- every 6 days
- every 8 days
- every 2 days
- every 5 days
- every 9 days
- every 6 days at 3:00 am
- every 9 days at 8:00 am
FUN FACT: If you want to edit your personal crontab, just type: “crontab -e” at the command prompt..
In this article, you learned how to set up a cron job that runs every 3 days at 1:30 pm. 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 cron job cheat sheet for a list of hundreds of popular cron jobs.