The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
0 20 */3 * *
This cron command translates to the following (in Human-Readable format):
“Every 3 days at 8:00 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.
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 3 days at 8:00 pm“:
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 3 days at 8:00 pm for several reasons, including:
- Running a script to update data
- Sending out a report
Similar Cron Jobs
You might also want to run a crontab:
- every 4 days
- every 5 days
- every 10 days
- every 2 days
- every 10 days at 10:00 pm
- every 7 days at 3:00 pm
- every 4 days at 4:00 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 8:00 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 cron job cheat sheet for a list of hundreds of popular cron jobs.