Forum currently uses GMT 0 timezone.
Nope, it's GMT +1 at the moment. GMT/UTC doesn't change for DST, it's our offsets that change.
Keeping the forum time at ±0 makes sense, as when (if) DST changes differs around the world.
Also, countdowns use forum time as base, so keeping it at GMT±0 would be better.
Does the time zone detection thing detect Daylight Saving Time? We're having that right now in Canada.
It does, but only when you manually use it to check.