The Cron Job/Crontab
To have your task run at this frequency, use the following cron:
30 15 */4 * *
This cron command translates to the following (in Human-Readable format):
“Every 4 days at 3:30 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 typically used for automating tasks, such as running backups or sending emails.
A crontab (also known as a “cron table”) is a file that contains a list of commands that are executed at specified times.
Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every 4 days at 3:30 pm“:
FUN FACT: Each user on a system can have their own crontab, and commands in them will be executed as that user..
You might want to set up a crontab or cron job to run every 4 days at 3:30 pm for several reasons, including:
- Check for updates to a software package and download if available
- Run a daily backup of user data
- Generate statistics about website usage
- Send out a daily email digest of news articles
Similar Cron Jobs
You might also want to run a crontab:
- every 2 days
- every 10 days
- every 8 days
- every 6 days
- every 8 days at 12:30 am
- every 6 days at 11:30 pm
- every 9 days at 4:30 pm
FUN FACT: When editing your crontab, it is important to use a text editor that supports Unix-style line endings (LF), as opposed to Windows-style line endings (CRLF)..
In this article, you learned how to set up a cron job that runs every 4 days at 3:30 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 cron job cheat sheet for a list of hundreds of popular cron jobs.