Daylight savings time - well, I would think its to have the optimum amount of daylight in order to continue daily activities and still get all kinds of things done, daily, during each day, in the daylight..............
Here in JPN we don't do daylight savings. In the summers, the comes up at 4am and stays later in the evening. During the winter, like now, the sun rises around 7am and sets around 4pm. Don't ask me how or why and I'm sure latitude has a lot to do with it. Weather and clouds greatly affect the light.
I can't say either way whether I like it or not. I'm glad I don't have to adjust for 1hr twice a year. Then again, that all kicks in for payback when we travel back to the States - traveling 10-15hrs sux, not to mention the week after.
If the effort is put into always trying to keep up with the sun, then wake up with the sun and go down with the sun, but those times will continuously change throughout the year, you'll be waking up earlier or later, as per the daylight savings time "plan". Funny thing is, it doesn't matter, with or without daylight savings you still lose daylight because you can't control the sun or the seasons.