GMT is Greenwich mean time; it's what time it is in London, England. If you're running in Windows, dbl click on the clock in the lower right hand corner of your screen; when the "Date/Time Properties" box pops up at the bottom there's a "Time Zone" drop down menu. It should show what time zone your're in, and it has how many hours away from GMT you are. (i.e., I'm in the Pacific Time Zone and the display in this box says "GMT -08:00"); so I just do the math to figure out what time it REALLY is!!
A database I use at my work also utilizes GMT for recordkeeping; I agree it's confusing.
Hope this helps.