The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
30 20 */3 * *
This cron command translates to the following (in Human-Readable format):
“Every 3 days at 8:30 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 jobs are commonly used to automate system maintenance or administration tasks, such as running backups or sending emails.
A crontab is a file containing commands and instructions for the cron daemon to execute. The crontab is used to schedule jobs (commands or shell scripts) to run periodically at certain times or dates.
Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every 3 days at 8:30 pm“:
FUN FACT: When configuring a cron job, you can specify the minute, hour, day of the month, month and day of the week when it should run – this gives you a lot of flexibility in terms of when your task will be performed automatically!.
You might want to set up a crontab or cron job to run every 3 days at 8:30 pm for several reasons, including:
- Backing up your data
- Generate reports
- Restart a service
- Backup a database
Similar Cron Jobs
You might also want to run a crontab:
- every 7 days
- every 1 day
- every 6 days
- every 5 days
- every 4 days
- every 3 days
- every 3 days at 8:30 am
- every 3 days at 2:00 am
FUN FACT: Each user on a system can have their own crontab, and commands in them will be executed as that user..
In this article, you learned how to set up a cron job that runs every 3 days at 8:30 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.