Daylight Saving Time (DST) schedule for the US states that observe summer time is:
2 a.m.local time on the second Sunday in March to 2 a.m. on the First Sunday of November.
Daylight Saving Time, for the U.S. and its territories, is NOT observed in Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and the state of Arizona (not the Navajo Indian Reservation, which does observe it). Navajo Nation participates in the Daylight Saving Time policy due to its large size and location in three states.
The United States spans six time zones. It shares four time zones with Canada (Eastern Time, Central Time, Mountain Time and Pacific Time).
Hawaii Time and Alaska Time are separate time zones.
(Note: in 2007, Daylight Saving Time was extended one month and a new rule started being implemented)