A sure sign that spring's on the horizon: One hour less shut-eye tonight no matter when you turn out the lights. Most people in the US are supposed to push the clock forward by 60 minutes before heading to bed. Daylight saving time officially begins at 2am tomorrow local time and will last until Nov. 1. The time change isn't observed by Hawaii, most of Arizona, Puerto Rico, the Virgin Islands, American Samoa, Guam, and the Northern Marianas. (More daylight saving time stories.)