How to use Cron Jobs

Cron jobs are commands run on a schedule and useful for many background tasks that need to run periodically.

Written by Chris Oliver
Updated over a week ago
Hatchbox creates cron jobs by adding them to the system cron service.

Cron Format
For help formatting Cron jobs, check out

Cron Time Zones
Cron runs on the system time zone, which is UTC by default. Your server may be on a different time zone. 

To can see which timezone your server is configured for, run this command over SSH:
We recommend keeping the timezone as UTC and adjusting your cron times accordingly.

To change the system timezone, you can reconfigure tzdata and restart cron.
sudo dpkg-reconfigure tzdata
sudo service cron restart
Cron Logging
It's up to you to have your cron job log to a file. Hatchbox only installs cron jobs which do not have any special logging like processes do.

Whenever Gem
The "whenever" gem is a Rubygem that allows you to specify your cron jobs in Ruby code.

If Hatchbox detects whenever is installed and finds a config/schedule.rb file, it will run whenever to update the crontab.
Note: Cron jobs from whenever will not be visible in the Hatchbox UI.

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