If your whole application environment is working within one particular timezone, then you are a happy man. Sometimes, especially when you are performing synchronizations with partners from different timezones, and those timezones are changing their time basing on the DST rules. This might be a nightmare, when your scheduled task change their execution time back and forth by one hour every time they want. Simply saying: you may adjust those time manually, it is doable, but please, do you want to do this up to four times a year? What a horrible loss of time! There are two approaches nice and hard , which one is applicable for you? It depends on the cron compilation configuration. Check it by calling: man 5 crontab in console. Of course, you know how to configure cron, scroll down up to example, and when you see something like this: # mail any output to `paul', no matter whose crontab this is MAILTO=paul # CRON_TZ=Japan # run five minutes after midnight, every day 5 0 * *...