It's about that time again to "fall back" and gain an extra hour of sleep.

Daylight saving time ends Sunday at 2 a.m., but most will set their clocks back one hour before going to bed Saturday night.

Some states and territories don't observe daylight-saving time and thus won't have to worry about changing their clocks back.

Those are Arizona, Hawaii, Puerto Rico, the Virgin Islands, American Samoa, Guam and the Northern Marianas.

Daylight saving time will "spring forward" next March 13.