Where do you get 4 times a year? If the CM15 is not plugged in, you only need to plug it in Saturday night when DST begins (at 2:00AM) and unhook it Sunday, then repeat the process when DST ends on the Saturday and Sunday. You do have clear the interface and reload it each time.
I keep my 15 plugged in 365 days a year, 366 on the leap years, so I don't have to do the plug/unplug routine.