Daylight Savings

The weekend has arrived.  I am not sure about the DST change this weekend.  Every year we spring forward and fall back an hour.  What is the reason for it?  Arizona does not do it.  Why do other states that do DST have to?  I find it redundant and kind of silly to be honest.  After a long winter, it seems that putting one hour ahead of time seems to claim the bodies of the aged, frail, and energetic at the same time for a few days while the time change from Winter to Spring takes it sweet time to energize us somehow again.  Not looking forward to having to change the clocks tomorrow night.