Problems with Daylight Saving Time
Yesterday, the Senate unanimously passed The Sunshine Protection Act, which is a bill that makes Daylight Saving Time permanent in the U.S.
This isn't the first time a permanent daylight saving time (DST) has been proposed. Some countries already have it: Belarus, Iceland, Argentina, and Morocco to name a few. Russia implemented it in 2014 but switched back.
There's some supporters who believe that DST saves energy and gives us more leisure time (in the daylight). Opponents have made many (unproven so far) claims about the disruption of human circadian rhythms. Farmers hate DST because their harvests are closely tied to the sun and their animals don't shift their schedules.
It's even complicated to calculate. Within the United States, Arizona doesn't recognize DST (but the Navajo Nation, which within Arizona, does). Programs often have to store large amounts of timezone data just to function. In 1993, there was a steel factory in Germany that had an incident after the system didn't properly account for DST and allowed the molten steel to cool for one hour less than it should have. Of course, they should have just been using Unix time.