(FORTUNE Magazine) – Grab your muskets and home amputation kits! Once again, disunity boils among the states. Arizona, Hawaii, and most of Indiana don't follow daylight-saving time. Why the rogue factions?

The Uniform Time Act of 1966 established DST nationally from April to October, but individual states were allowed to opt out. Arizona switched back to standard time in 1968 after residents complained that the extra hour of sun led to even sweatier nights and made it more difficult to put kids to bed early. "We have more sunshine than we know what to do with," says Don Langlois, a history librarian at Arizona State Library. "There's no point in saving it." Hawaii's proximity to the equator--and year-round sunshine--makes DST pointless. And Indiana farmers, tired of doing their morning plowing in the dark, persuaded the state assembly to opt out in 1971. (Fifteen of the state's 92 counties continue to observe DST nevertheless.) Guess Einstein was right: Time really is relative.

--Reed Tucker