The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
20 */9 * * *
This cron command translates to the following (in Human-Readable format):
“Every 9 hours at 20 minutes past the hour.”
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 text file containing a list of commands that are executed at specified times. The commands in the crontab are executed by the cron daemon, which runs in the background and checks for new entries every minute.
Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every 9 hours at 20 minutes past the hour“:
FUN FACT: Cron jobs are often used to perform regular maintenance tasks, such as running backups or sending out reports..
You might want to set up a crontab or cron job to run every 9 hours at 20 minutes past the hour for several reasons, including:
- Automatically update a software package
- Perform a nightly backup
- Generate daily reports
- Refresh data from an external source
Similar Cron Jobs
You might also want to run a crontab:
- every 9 hours
- every 12 hours
- every 10 hours
- every 6 hours
- every 3 hours
- every 3 hours at 30 minutes past the hour
- every hour between 8:00 pm and 11:00 pm
- every hour between 9:00 pm and 11:00 pm
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 9 hours at 20 minutes past the hour. 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 crontab cheat sheet for a list of hundreds of popular cron jobs.