The clock has separate battery backup.
It is very important for the clock to be set correctly when using lockouts.
Remember to change from Standard time to Daylight time (and back) when using lockouts. Otherwise, it is not necessary to be set accurately for proper operation.
Press either ARROW key to change day of week.
Repeat 2 and 3 for hour, minute, and am/pm.
Changes are effective only after pressing the final SET.