The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
0 15 */3 * *
This cron command translates to the following (in Human-Readable format):
“Every 3 days at 3:00 pm.”
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.
Crontab files are typically stored in the /etc/crontab file, but they can also be stored in individual user’s home directories. To edit your own crontab file, you can use the command “crontab -e”. This will open up the file in your default text editor.
Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every 3 days at 3:00 pm“:
FUN FACT: If you want to edit your personal crontab, just type: “crontab -e” at the command prompt..
You might want to set up a crontab or cron job to run every 3 days at 3:00 pm for several reasons, including:
- A cron job to run a backup every three days
- A cron job to send an email report every three days
- A cron job to check for updates every three days
- A cron job to clean up temporary files every three days
Similar Cron Jobs
You might also want to run a crontab:
- every 3 days
- every 1 day
- every 8 days
- every 7 days
- every 4 days
- every 5 days at 9:00 pm
- every 3 days at 4:30 am
- every 5 days at 2:30 pm
FUN FACT: If you want to see what commands are scheduled in your crontab, type: “crontab -l”.
In this article, you learned how to set up a cron job that runs every 3 days at 3:00 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 crontab cheat sheet for a list of hundreds of popular cron jobs.