Before I retired I had a similar job to Ultrarunner and had to change hundreds of clocks twice a year. Now I have two, the microwave and the coffee machine and that's done fore the wife as I don't really care what time it is. Not sure if I'll have to change the clock in my truck or if it does so automatically. Haven't worn a watch since retiring. I also have a clock in my tractor radio and garage. They each give the correct time for 6 months a year.