The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
30 21 */8 * *
This cron command translates to the following (in Human-Readable format):
“Every 8 days at 9:30 pm.”
What is a Cron Job & Crontab?
A cron job is a scheduled task that is typically executed automatically at a predetermined time or interval. Cron jobs are often used to perform routine system maintenance tasks, such as backing up files or databases, deleting temporary files, or sending email notifications.
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 8 days at 9:30 pm“:
FUN FACT: Cron jobs can be set up to run at specific times, or they can be configured to run periodically (e.g., every hour)..
You might want to set up a crontab or cron job to run every 8 days at 9:30 pm for several reasons, including:
- Sending out a reminder email to renew a subscription
- Generating a report of system usage for the past week
- Backing up user data from the past week
- Clearing out temporary files that are no longer needed
Similar Cron Jobs
You might also want to run a crontab:
- every 7 days
- every 8 days
- every 4 days
- every 2 days
- every 3 days
- every 1 day
- every 1 day at 3:00 am
- every 9 days at 4:00 pm
- every 6 days at 2:30 am
FUN FACT: Cron is one of the most powerful tools available on a Linux system – use it wisely!.
In this article, you learned how to set up a cron job that runs every 8 days at 9:30 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 crontab cheat sheet for a list of hundreds of popular cron jobs.