Daylight saving time ends Sunday, Nov. 3, at 2 a.m.  That means this weekend, you will be setting your clock back one hour, following the adage of “spring forward, fall back.”

The official time to do that would be 2:00 AM Sunday. However, most simply change their clocks before bed Saturday night so everything is correct Sunday morning. It's also a great reminder to check the batteries in your smoke and carbon monoxide detectors.

Hopefully, the “extra” hour gives you a chance to catch up on the sleep you lost when you moved the clocks ahead in April.

How daylight saving time got its start

In an effort to save resources during World War II, the U.S. made daylight saving time mandatory for the whole country. And it was observed the entire year. Now it's optional for states. For example, if you travel from California to Arizona in the winter, you'll lose an hour. since they don't observe the time change.

Some studies have shown that extending daylight saving time results in a reduction in energy consumption; other studies suggest just the opposite.