Come early Fall, many people in the U.S. wonder when exactly that old phrase "Fall back, Spring forward" will come in handy for daylight savings. In 2012, Daylight Saving Time, as it is formally called, ends on Sunday.

Daylight Saving Time for 2012 is coming to an end this weekend on Sunday, Nov. 4, when clocks will be set back at 2 a.m. giving us an extra hour of sleep.

On Sunday at 2 a.m., you'll move clocks back one hour and gain 60 minutes of extra time, sleep or partying that morning. However, if you go to bed early, it is recommended to set clocks back an hour before, to ensure the proper time when you wake up. Some electronic devices, like smartphones, automatically change to daylight saving time, so no need to set those iPhones back.

However, many U.S. states do not observe daylight saving time, like Arizona, Hawaii, Puerto Rico, the Virgin Islands, American Samoa, Guam, and the Northern Mariana Islands.

For many years, Daylight Saving began much earlier than November. In 2005, the Energy Policy Act altered the start and end dates of daylight saving time. The new act went into effect in 2007 and changed the dates in an attempt to save energy; From then on, clocks were set forward on the second Sunday of March instead of the first Sunday of April and set back one hour on the first Sunday in November rather than the last Sunday of October.

Many fire departments encourage U.S. residents to use Daylight Saving as a time to change batteries in smoke and carbon monoxide detectors, as well, as a precaution.