Cron Job Every 4 Hours At 40 Minutes Past The Hour (Crontab)

This page will help you quickly and easily set up a cron job to run every 4 hours at 40 minutes past the hour.

The Cron Job/Crontab

To have your task run at this frequency, use the following cron:

40 */4 * * *

This cron command translates to the following (in Human-Readable format):

“Every 4 hours at 40 minutes past the hour.”

What is a Cron Job & Crontab?

A cron job is a Linux utility used for scheduling the execution of commands or scripts at a specified time and date. Cron is typically used for system maintenance or administration, such as running backups or log rotation.

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.

Cron Fields

Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every 4 hours at 40 minutes past the hour“:

  • Field 1: (40) indicates that the task will be run at minute 40.
  • Field 2: (*/4) indicates that the task will be run every 4 hours.
  • Field 3: (*) indicates that the task will be run every day of the month.
  • Field 4: (*) indicates that the task will be run every month.
  • Field 5: (*) indicates that the task will be run every day of the week.
  •  

    FUN FACT: Cron jobs are named after the Greek god of time, Chronos – so now you know where the name comes from!.

    Use Cases

    You might want to set up a crontab or cron job to run every 4 hours at 40 minutes past the hour for several reasons, including:

    • Run a script to update software every 4 hours
    • Run a script to backup data every 4 hours
    • Run a script to send out an email report every 4 hours
    • Run a script to check for new users every 4 hours

    Similar Cron Jobs

    You might also want to run a crontab:

    FUN FACT: If you need to temporarily disable a cron job, you can simply comment out the line in the crontab file that corresponds to that particular task..

    Wrapping Up

    In this article, you learned how to set up a cron job that runs every 4 hours at 40 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 cron job cheat sheet for a list of hundreds of popular cron jobs.

    SHARE:

    Leave a Comment