The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
0 2-21 * * *
This cron command translates to the following (in Human-Readable format):
“Every hour between 2:00 am and 9:00 pm.”
What is a Cron Job & Crontab?
A cron job is a task that is scheduled to run at a specific time or interval. Cron is a Linux utility that allows tasks to be automatically run in the background at regular intervals. These tasks are often called “cron jobs.”
A crontab is a file that contains a list of commands that are to be executed at specified times. The commands in the crontab are executed by the cron daemon.
Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every hour between 2:00 am and 9:00 pm“:
FUN FACT: When troubleshooting issues with cron jobs, it can be helpful to run them manually from the command line – this will allow you to see any error messages that might be generated..
You might want to set up a crontab or cron job to run every hour between 2:00 am and 9:00 pm for several reasons, including:
- Check for updates on a website
- Send an email to a user
- Run a backup script
Similar Cron Jobs
You might also want to run a crontab:
- every 6 hours
- every 5 hours
- every 10 hours
- every 11 hours
- every 9 hours
- every 12 hours
- every hour between 12:00 am and 5:00 pm
- every hour between 8:00 am and 10:00 pm
- every 9 hours at 1 minutes past the hour
FUN FACT: One common use for cron jobs is to send out email reminders or notifications based on certain events (such as an upcoming deadline)..
In this article, you learned how to set up a cron job that runs every hour between 2:00 am and 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.