Don't be a lefty moron. Let them NPC. Don't fall for the twice a year bandwagon.
We measure time with the sun. From seconds to lightyears. Daylight savings is another measurement of time.
I could use the daylight savings saying "it makes no sense" for every measurement of time we use.
It's to match up with the timing of sunrise. Earth's tilt and all.
You'll be very depressed how few even know how seasons work.