The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
0 0 20 */4 *
This cron command translates to the following (in Human-Readable format):
“Every 4 months on day 20 of the month.”
What is a Cron Job & Crontab?
A cron job is a time-based task that is set to run at specific intervals. This can be anything from running a script every hour to backing up a database every day. Cron jobs are typically used for maintenance or automation purposes.
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 4 months on day 20 of the month“:
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 4 months on day 20 of the month for several reasons, including:
- To run a script every 4 months on day 20 to check for updates
- To run a backup every 4 months on day 20
- To send out an email reminder every 4 months on day 20
Similar Cron Jobs
You might also want to run a crontab:
- every 4 months
- every 6 months
- every 1 month
- every 2 months
- every 3 months
- every 5 months
- every 3 months on day 22 of the month
- every 1 month on day 5 of the month
FUN FACT: Cron jobs are named after the Greek god Chronos, who represents time itself..
In this article, you learned how to set up a cron job that runs every 4 months on day 20 of the month. 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.