My new 8.1 has the time set for Central Time (USA) and for some strange reason it also shows GMT to be running one
hour ahead. I have my HP Notebook set with three different clocks (local, GMT and Prague). And they are all running
one hour ahead. Anyone else? ???
Same here for Mountain Time Zone. I just adjusted it so it was right on my end. 
I get that but I also have two other clocks running and one of them is GMT.
GMT is also off by one hour. The other one, set to CET (Prague) is off by one hour too.