It is even more complicated
The forum software does not know anything about time zones and daylight savings, it has just two values - the main difference between computer time and forum main time and user based difference between forum main time and his/her time.
The computer time itself reflects the CET during winter (5 months) and CEST during summer (7 months). The SMF main difference is set to -2 - so it is at GMT during summer but Azores islands (??) during winter!
The users (like myself) in Central Europe should have +2 in their profile - and the time will be correct whole year around. It is similar for most users in North America and some in Asia. Unfortunately for users which have different daylight switching days, no daylight time at all (or even the opposite daylight change in southern hemisphere!) the time of the messages could change during the year. They can adjust their offset manually but this is far from ideal solution.
There is no really correct solution in SMF for this rather complicated problem - and if I will change the main time offset (to keep the time the same) most of our users will be out of sync and will be forced to do the same
Hope this helps
Pavel
