(CNN)In the fall, waking up to realize Daylight Saving Time ended overnight might feel great — especially when you get that extra hour of sleep.
In the spring, the transition is reversed, with the panic of waking up unexpectedly an hour late for whatever is scheduled that morning.
Yep, it's Daylight Saving Time again.
Daylight Saving Time starts on the second Sunday in March at 2 a.m. and ends on the first Sunday in November at 2 a.m in the United States. This year, that's March 14, when we set our clocks ahead one hour, through November 1, when we set them back one hour. And those of you in Europe aren't exempt, but you will have to wait two more weeks for March 28.
However, not everyone observes the tradition in the US — Hawaii and Arizona don't — nor do China and Japan. About 70 countries participate in this twice yearly time-changing exercise.
Daylight Saving Time is an enigma for many people, who wonder why we do it. Although it's intended to save energy and make better use of daylight, it's recognizable to most as something they might forget, which could cost them accidentally sleeping in or waking up less rested than they would have hoped.
Rather than struggle through the biannual switch, Dr. Shalini Paruthi advises people to prepare for the change, so it's not so disruptive to our sleep schedules.