The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
30 15 */3 * *
This cron command translates to the following (in Human-Readable format):
“Every 3 days at 3:30 pm.”
What is a Cron Job & Crontab?
A cron job is a time-based task that is set to run at a specific time or interval. These jobs are usually used for automating tasks, such as running backups or sending emails. Cron is the name of the program that enables users to schedule these jobs.
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 3:30 pm“:
FUN FACT: Cron is one of the most versatile tools in a Linux administrator’s toolbox..
You might want to set up a crontab or cron job to run every 3 days at 3:30 pm for several reasons, including:
- Run a backup every three days at 3:30 pm
- Automatically update a blog every three days at 3:30 pm
- Check for new software updates every three days at 3:30 pm
- Send out a newsletter every three days at 3:30 pm
Similar Cron Jobs
You might also want to run a crontab:
- every 7 days
- every 3 days
- every 8 days
- every 4 days
- every 6 days
- every 5 days
- every 2 days at 6:00 am
- every 9 days at 8:30 am
- every 7 days at 12:30 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!.
In this article, you learned how to set up a cron job that runs every 3 days at 3:30 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.