Linux Crontab with example

Crontab is used to schedule the command to run at a specific time on your system. For example, you may want to take a backup of your database, reboot your system, to run a script at a specific time. In this tutorial, I will show how to configure cronjob on your system. You can use this tutorial to configure on Ubuntu, Linux mint, centos, etc. I will also show you how to set up the different timings on crontab.

Crontab syntax

The crontab has a total of 6 fields. The first 5 field is for setting the timings and the last field is for setting the path of the script/commands.
Below is the picture that demonstrates what each field/asterisk (*) do.


Create or update crontab

To create or update crontab enter the following command.

crontab -e

The above command will open the crontab shell where you can edit or update the cronjob

List all the crontab

To list all the crontab entries use the following command

crontab -l

Crontab examples:

Below are the examples of crontab that you can use

Cronjob timings Cronjob Config Cronjob Description
Every minute * * * * * Cronjob will run every minute
Every five minutes */5 * * * * Cronjob will run every five minutes
Every Ten minutes */10 * * * * Cronjob will run every ten minutes
Every Thirty minutes */30 * * * * Cronjob will run every Thirty minutes
Every hour/hourly 0 * * * * Cronjob will run every hour
Every day at 1:30 30 1 * * * Cronjob will run every day at 1:30
Twice a day at 01 AM and 2 PM 00 01,13 * * * Cronjob will run twice a day at 01 AM and 02 PM
Weekly on Monday 0 01 * * MON Cronjob will run weekly on Monday at 01 AM
Every Year January 0 0 1 1 * Cronjob will run every year on January 1 at 12:00 AM
Every month 0 01 1 * * Cronjob will run every month at 01:00 AM