This is a problem that is acute in our FC. First of, don't confuse GMT with BST. The servers inner workings are in GMT. That doesn't change when the summertime occurs. That's also why the maintenance times they list seem to be a bit off. Even in England, if the maintenance time is scheduled to 8 am GMT, on summer time England is actually in BST, which is British Summer Time. And yes, even some brits I've met don't know this difference and assume their time is GMT always. Essentially, even England (and the rest of that timezone if they follow summer time) is on +1 to GMT during summertime. Same for all other timezones that follow summer time. Finland for example is +2 to GMT, and during summertime, Finland is actually +3 to GMT while they still are just two hours ahead of the rest England since everyone follows summertime. Since the server is in GMT throughout the year, on winter my daily reset is at 5pm (3pm ST that is presented to me, 3pm GMT), but during summer it jumps to 6pm my time (4pm ST that is presented to me, 3pm GMT), all other timed events following the cue. As you might notice, the time in GMT is still the same. That is sensible since any servers inner clocks shouldn't be following any summertime nonsense.
Why is this a problem? Because the ST we are presented is not the server time, which should universally be GMT. Instead it calculates our timezone amount difference to the GMT, which in my case is +2, and applies it throu out the year, without regard that half of the year my current time actually has three hour difference to actual GMT. (Even if I still have only two hour difference to England since they too follow the summertime.) However not all countries across the world follow the summertime, which contains a good amount of my FC mates. Since their local time doesn't change, the difference shows in the presented ST. My ST is always shown to be -2 hours to my local time. Which half of the year is not actual GMT. While theirs ST is -10 hours to the their local throughout the year which also is actual GMT the whole year . There is half a year discrepancy there when those who follow summertime are presented different ST by the game, as those who don't follow it. It's hard to plan anything when we have the situation "your ST is better than my ST" since the actual ingame presented ST is different, even if everyone has set their timezones correctly. That is because the game uses a flawed method. It measures a difference in the time zone amount (essentially location) and applies it to a local time, which due the summer time changes, while location does not.
The solution would be, as someone suggested, the game client asking on logon from the server what the ST is, counting the difference to the local time, and using that difference throughout the session. Assuring that ST is the same for everyone, regardless what their local time might be.
Edit: or even simpler, just have the ST always show GMT for everyone, regardless what their local times show. That way everyone would see exactly same time which is about the only usefull purpose for ST.
Sorry for long post.
Edit: @Wade, I wouldn't pay too much attention to maintenance finish times. It mght very well be they just have had exactly one extra hour planned for stuff that goes wrong, and when everything goes smoothly they can skip that. I can say it started exactly at the time, by GMT as it was marked. The end times are always fluid.