The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
0 21 */4 * *
This cron command translates to the following (in Human-Readable format):
“Every 4 days at 9:00 pm.”
What is a Cron Job & Crontab?
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 4 days at 9:00 pm“:
FUN FACT: If you need to delete a cron job, simply remove the corresponding line from the crontab file and save your changes..
You might want to set up a crontab or cron job to run every 4 days at 9:00 pm for several reasons, including:
- A cron job that runs every 4 days at 9:00 pm could be used to send out a reminder email to customers about an upcoming event.
- A cron job that runs every 4 days at 9:00 pm could be used to generate a report of website activity for the past four days.
- A cron job that runs every 4 days at 9:00 pm could be used to update a software application or plugin.
Similar Cron Jobs
You might also want to run a crontab:
- every 3 days
- every 1 day
- every 5 days
- every 10 days
- every 8 days
- every 9 days
- every 5 days at 4:30 am
- every 3 days at 2:00 am
FUN FACT: The most common way to edit cron jobs is using the crontab command – this stands for “cron table,” and it contains all the information about when your tasks should be executed..
In this article, you learned how to set up a cron job that runs every 4 days at 9:00 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.