Server time should be the local time in the time zone where a server is located.
However, on Travian the time indication near top left of screen says "Server time: .... (GMT+...)" where it should say "Your time: .... (Server time + ...)" if the numbers are to treated as correct. For example, where the default time (until you set your preferences) is UTC+10 (Sydney, Australia) and your time zone is UTC+8, two hours to the west, noon in your part of the world (2 pm in Sydney) after you set your preferences to UTC+8 will show as "Server time: 12.00.00 (GMT-2)", whereas it should say "Your time: 12.00.00 (Server time - 2)" or preferably "Your time: 12.00.00 (UTC+8)"
Troops have been lost through Travian's incorrect use of "GMT" in that context. Battle planners in an alliance asked all members to set their preferences to GMT so that attacks would be coordinated, with no chance of mistake. Some players trustingly thought "GMT" meant what it said, whereas it probably meant "Server time in Germany". Others set their preferences to true GMT by counting from their own timezones. Relatively weak armies with catapults arrived at a target before a carefully orchestrated clearance had happened, instead of a few seconds after, and were cut to pieces achieving no good for the alliance.