GMT is Greenwich Mean Time. To find out what your GMT is (GMT+1 or whatever) if you're using windows, double click on your computers clock in the bottom right of your screen and look at the bottom of the window that opens. There should be a little bit which says "Current Time Zone: GMT *plus/minus a number*" that's your GMT, if you can tell us what it is it would be helpful.
P.M.
I can only express puzzlement that borders on alarm.