When it’s time to “fall back,” the clocks will turn back one hour, going from 2 a.m., to 1 a.m. Daylight saving time is in effect for 238 days, or about 65% of the year, according to National Institute of Standards and Technology.

According to the Astronomical Applications Department of the U.S. Naval Observatory, daylight saving time is when clocks are changed to one hour ahead, which began on Sunday, March 10 of this year.

Daylight saving time, the controversial practice that sees Americans adjust their clocks twice per year, will end Nov. 3.