An off alarm clock means that a mobile phone can ring on time at the set alarm clock time after being turned off. The setting method of the mobile phone shutdown alarm clock is as follows: 1. Applications-Clock-Menu Keys-Start before alarm clock-Tick-tock. (Note: Please confirm that your mobile phone supports off alarm clock first) 2. After setting, if the phone is turned off, when the alarm clock is about to ring, the phone will automatically start ringing according to the alarm clock time you set.