The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
0 0 21 */5 *
This cron command translates to the following (in Human-Readable format):
“Every 5 months on day 21 of the month.”
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 typically used for automating tasks, such as running backups or sending emails.
Crontab is a file that contains commands and instructions for the cron daemon to execute. The crontab file is usually located in the /etc/cron directory. Each user on a system can have their own crontab file. The commands in the crontab files are executed by the cron daemon at the specified times.
Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every 5 months on day 21 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 5 months on day 21 of the month for several reasons, including:
- Updating software
- Running system maintenance tasks
- Generating reports
- Synchronizing data
Similar Cron Jobs
You might also want to run a crontab:
- every 1 month
- every 5 months
- every 2 months
- every 4 months
- every 3 months
- every 6 months on day 3 of the month
- every 6 months on day 1 of the month
FUN FACT: A common use for cron jobs is to generate periodic reports – for example, you could set up a cron job to automatically generate and send out a report on website traffic statistics every week..
In this article, you learned how to set up a cron job that runs every 5 months on day 21 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.