5 Questions: Time to fall back The Time and Frequency Division
of the National Institute of Standards and Technology, which
provides official time to the United States, answers questions
about the twice-annual time change. Q: What is daylight saving
time? A: Daylight saving time is the period of the year when
clocks are moved one hour ahead. In the United States, this has
the effect of creating more sunlit hours in the evening during
months when the weather is the warmest. The transition from
daylight saving time to standard time effectively moves one hour
of daylight from the evening to the morning. Q: When is daylight
saving time? A: Daylight saving time begins each year on the
second Sunday in March at 2 a.m. (local time). Clocks must be
moved ahead one hour when daylight saving time goes into effect.
The changeover back to standard time occurs on the first Sunday
in November at 2 a.m. (local time). Clocks must be moved back
one hour. Q: Didn’t daylight saving time used to end in October,
not November? A: