Blame the Kiwis and Germany during World War I (background article in CSM)

from Christian Science Monitor article about "Daylight Savings Time" -- (posted Nov. 6 before overnight shift)

The "Spring forward, Fall back" ritual was codified in the Uniform Time Act of 1966. States can opt out, of course. Hawaii and Arizona have said no thanks to the time changes that kick in on the second Sunday in March and the first Sunday in November.

But the rest of the country, including the once temporally bifurcated Indiana, are now on board.
If the twice-a-year clock tweaking seems a bit of a hassle, don't blame Ben Franklin, the oft-cited originator of the policy. He did offer up a version, but as satire – a dig at folks in Paris who apparently didn't hew to the "early to bed, early to rise" mantra he crafted.
Blame the Kiwis, instead. Back in 1895, one George Vernon Hudson, post-office clerk by day, entomologist during his off hours, offered up the notion of a two-hour time shift to the Wellington Philosophical Society as a means "to bring working-hours of the day within the period of daylight." Many were the tut-tuts, according to a brief record of his presentation.
Three years later, he offered up a refined version of the idea, arguing that "in this way the early-morning daylight would be utilised, and a long period of daylight leisure would be made available in the evening for cricket, gardening, cycling, or any other outdoor pursuit desired."
Perhaps not wanting to sound too self-serving, he declined to list his his favorite off-duty activity -- bug hunting. That presumably fell under the catch-all "any other outdoor pursuit."
It would be another 19 years before a nation would formally adopt the idea – Germany during World War 1 – as a way to cut down on energy demand, an aspect of Daylight Saving Time that is still a subject of dispute.