Sunday marks the return from Daylight Saving Time back to Standard Time; you should set your clocks back one hour before going to bed on Saturday night, before the time change beginning at 2:00 a.m.

The good news is you’ll get an extra hour of sleep in the morning on Sunday; but you may be confused for a while, as you get used to the sun setting earlier and find yourself recalculating what time it is now from what time it was the day before.

Daylight Saving Time is observed in 48 states and the District of Columbia; Hawaii remains on its own Standard Time all year round, as does Arizona with the exception of the Navajo Nation.

No U.S. dependencies follow Daylight Saving Time.

It’s also common in Europe and parts of the Southern Hemisphere; but countries near the Equator don’t use it, because sunlight there doesn’t vary enough to make it worthwhile.