Millions of Americans will gain an hour of sleep this weekend when the twice-a-year time change commonly known as daylight savings ends for 2026. Most of the U.S. will "fall back" an hour when the clocks change at 2 a.m. on Sunday.

Here's what to know about what's formally known as daylight saving time as it ends for the year:

What is daylight saving time, and why do we have it?

Daylight saving time is the period during the year, from March to early November, when the majority of the U.S. operates one hour ahead of standard time.

The move effectively "saves" an hour of daylight from the morning and adds it to the evening during the spring and summer months when the days are the longest. In the fall and win...