The annual Daylight Saving Time season kicks off on Sunday, March 8th.
At 2 a.m., the official time and automated clocks in most of the United States and some other parts of the world will jump ahead an hour.
Daylight Saving Time is not as ubiquitous around the world as it is in the United States. Of the 195 nations recognized by the United Nations, about 70 of them observe Daylight Saving in some capacity.
In the United States, only two states choose to not observe DST. Both Arizona (with the exception of the Navajo Nation) and Hawaii, two southern states that generally receive a lot of sunlight and as such, wouldn't get much use out of the practice, do not change their clocks with the rest of the country. They are joined by a few other U.S. territories, such as Puerto Rico, the Northern Marina Islands, the U.S. Virgin Islands, American Samoa, and Guam.
There is no blanket federal law requiring following the Daylight Saving Time practice. The 1966 Uniform Time Act did nationalize dates for DST to begin and end, but did not require states to comply.
