Daylight saving time ends Sunday -- which means we'll get an extra hour of sleep this weekend, but face darker commutes home starting Monday.
The period ends at 2 a.m. Sunday. When daylight saving time switches back to standard time, clocks "fall back" one hour.
The transition, the National Institute of Standards and Technology says, "effectively moves one hour of daylight from the evening to the morning."
Not all places get extra sleep or have to remember to adjust clocks this weekend. Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and Arizona (with the exception of the Navajo reservation) all don't observe daylight saving time.
The switch means mornings will be brighter, but the sun will set earlier at night. That raises a variety of issues, some say.
AAA is warning motorists, bicyclists and pedestrians that evening commutes will start taking place in darkness, making evening travels more dangerous. In Pennsylvania, 65 percent of pedestrian traffic fatalities last year happened in non-daylight hours, according to AA Mid-Atlantic.
And Columbia University psychiatry professor Michael Terman tells Weather.com that the dark evening hours can lead to seasonal affective disorder, a type of depression commonly called SAD, or simply experience the "winter blues."