So What's The "Saving" Part?

Daylight Savings Time ends up costing homes more in air-conditioning bills than they save in lighting less, according to a pair of researchers at the University of California-Santa Barbara. They studied residences in Indiana, which finally adopted DST in 2006.

From The Wall Street Journal:

Their research showed that while an extra hour of daylight in the evenings may mean less electricity is spent on lights, it also means that houses are warmer in the summer when people come home from work. Conversely, during daylight-saving time's cooler months, people may crank up the thermostats more in the morning.

This is exactly the reason Arizona doesn't go on DST. We don't need our homes any hotter in June, and if you're only using evaporative cooling (a.k.a. "The Swamp Box"), it's worthless once the monsoon rolls around in July. But it's also strange being on Pacific Time for six months of the year and Mountain Time for the rest. Arizona's far enough to the West Coast. Why not just stay on Pacific Time year-round?

UPDATE: The Navajo reservation, which stretches into Arizona, New Mexico and Utah, goes on DST so everybody's on the same time. However, the Hopi Nation in Arizona, which is surrounded by the Navajos, stays with Arizona's standard time. That's just as bad as Indiana before DST, when a handful of counties switched and the rest of the state didn't.