Rule 1 applies to all time zones in the U.S. and begins on the first Sunday on, or after March 8 at 2:00 a.m. with a 01:00 increment. Daylight Saving Time (DST) stops on the first Sunday on, or after November 1 at 2:00 a.m., also with a 01:00 increment used as a decrement when switching back to standard time. This is the default.
The increment is added to standard time at the specified start time, and the clock time shifts by that increment. For example, for 01:59:00 to 01:59:59, the clock time shows 01:59, and at 02:00 the clock shows 03:00.
On the stop date, the increment is subtracted from the specified stop time. For example, for 01:59:00 to 01:59:59 the clock time shows 01:59, and at 02:00 the clock shows 01:00.
Note:
You cannot delete a daylight saving rule if it is in use on either the Locations or Date and Time screens. However you can change any rule except rule 0 (zero).