Cron Job Every 30 Minutes (Crontab)

This page will help you quickly and easily set up a cron job to run every 30 minutes (every half an hour).

The Cron Job/Crontab

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

*/30 * * * *

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

“Every 30 minutes.”

What is a Cron Job & Crontab?

A cron job is a scheduled task that is typically executed by the operating system. Cron jobs are often used to automate repetitive tasks, such as backing up files or checking for updates.

Crontab files are stored in the “/etc/cron*” directories on most Linux systems. Each user has their own crontab file, and there is also a system-wide crontab file that can be used to schedule system tasks.

Cron Fields

Every cron job uses five fields. Here is an explanation of what each field does in this cron, which runs “every 30 minutes“:

  • Field 1: (*/30) indicates that the task will be run every 30 minutes.
  • Field 2: (*) indicates that the task will be run every hour.
  • 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.
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    FUN FACT: Cron is one of the most versatile tools in a Linux administrator’s toolbox..

    Use Cases

    You might want to set up a crontab or cron job to run every 30 minutes for several reasons, including:

    • Checking the status of a long-running process
    • Sending out a daily digest email
    • Performing maintenance tasks (e.g. database backups)

    Similar Cron Jobs

    You might also want to run a crontab:

    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)..

    Wrapping Up

    In this article, you learned how to set up a cron job that runs every 30 minutes. 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.

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