The Sysamdin !FAQ
dedicated to questions not frequently asked
Why shouldn't I schedule cron jobs between 01:00-03:00 in the morning?
Cron jobs run based on localized time. When daylight savings time occurs in the fall you experience the hour between 01:00-02:00 twice and your job will run twice. In the spring we jump from 01:59-03:00 and your cron job may not run at all!!! This is limited to Sundays.