As experiments have shown, Linux handles daylight savings if left on during the change if not set to UTC to begin with. Otherwise, if you tell it that your hardware clock is set to UTC, and it really is, it handles it by simply converting from the UTC to the selected time zone on the fly. Every document I have ever read on the subject says that if you run Linux only, you should set your clock to UTC and then select your local time zone. If you run Linux with DOS or Windows, you say no to the question about the hardware clock set to UTC and either leave the computer in Linux when the transition occurs so it can adjust the clock, or start it in the other OS after the change and let it handle it. I don't know, however, how it handles GMT. I don't know if it treats it like UTC or not.
