One of the arguments in favor of DST is that it conserves energy. The Master even includes this in his article about Daylight Saving.
What with all our computers, televisions, washing machines and what not, are there any studies proving that moving the clocks forward an hour conserves energy? Is it a substantial enough savings to make DST actually work, or is it just a holdover from the time when people went to bed with the sunset?
There is a 2001 California Energy Commission Study that looks into some data and hypothesizes the energy savings that we’d get if we extended DST during the summer and winter months. I’m not sure if it talks about savings over not having DST at all, however.
A combination of both, in a sense. Some of the old time schedules persist, and they are not energy efficient. Converting to daylight saving time makes the schedules more energy efficient.
Obviously, we could just change the schedules, but apparently, that would take a lot of energy 
WAG It was dreamed up by politicians so they could play a full 18 holes evenings for more months of the year!