This is something I have often commented on in various forums over the years. They always say that all times are in GMT (though you do get an option to choose your own time-zone off-set), but the fact is during Daylight Savings they are not! As I am in the UK, I have my time-zone set to GMT, but right now my BBS time is showing as GMT+1. In other words, it is showing the correct current time for me, but it should in fact be showing an hour earlier than my current time to be truly on GMT.
As a Radio Amateur, I have to fill my log-book in in GMT and am used to the fact that during the summer months I need to take an hour off the local time for it to be correct.
The confusion with GMT, which is supposed to be a time standard, is the main reason I never use it to advertise events.