The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
30 22 */3 * *
This cron command translates to the following (in Human-Readable format):
“Every 3 days at 10:30 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.
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 10:30 pm“:
FUN FACT: If you want to see what commands are scheduled in your crontab, type: “crontab -l”.
You might want to set up a crontab or cron job to run every 3 days at 10:30 pm for several reasons, including:
- Sending a reminder email every 3 days
- Backing up data every 3 days
- Generating reports every 3 days
Similar Cron Jobs
You might also want to run a crontab:
- every 7 days
- every 2 days
- every 5 days
- every 10 days
- every 4 days at 6:30 am
- every 2 days at 9:30 am
- every 9 days at 1:30 pm
FUN FACT: Cron is one of the most versatile tools in a Linux administrator’s toolbox..
In this article, you learned how to set up a cron job that runs every 3 days at 10:30 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.