Why have it?
Peak electricity usage in the summer is between 5pm and 9pm,
that is when they tell you to conserve power.
If the sun went down one hour earlier in the summer
it would be one hour cooler when people get home
from work and run their air conditioner. It would be cooler
when people go to bed even if they only had a fan and they
could sleep better. Air conditioners are probably the highest
power users, so wouldn't we save power if it got cooler
one hour earlier in the evening in the summer?