The time change, which officially came at 2 a.m. local time Sunday, promises an extra hour of evening light well into autumn.
It's also a good time to put new batteries in warning devices such as smoke detectors and hazard warning radios.
Some places don't observe daylight saving time. Those include Hawaii, most of Arizona, Puerto Rico, the Virgin Islands, American Samoa, Guam and the Northern Marianas.
Daylight saving time ends Nov. 3.
