Because Theia allows every member to independently choose which time zone dates and times are displayed in, it is important to have Theia configured to GMT (Greenwich Mean Time / London).

During a complete installation of Theia, the installer should have automatically calculated the offset between the server's local time and GMT, so you may not need to do a thing to get times to display properly.

If you do for some reason feel that the time is incorrect, first make sure that you have chosen your time zone correctly. Navigate to "settings", and make sure that the time zone which is selected is correct for your location. If at this time you still think times are incorrect on your site, then it's possible that Theia miscalculated the offset, in which case you can manually control this value.

Load up the tools page, and look in the "system configuration" group of tools for a tool reading "time configuration" (admin tool 161).

Things to consider

Theia stores all times in the database as LOCAL time stamps. This means, every time stamp stored in the database is local to wherever your server is in the world. The reason time stamps are saved as local times, as opposed to GMT stamps is because if you switch servers, you just need to readjust the time offset and everything will be displayed with the same times again.

When manually setting the time zone offset, you need to keep in mind that you should INVERT the difference of time between your server and GMT. For example, the SikoSoft server is located in Sweden (which is GMT+1). Instead of writing 1, you should instead write -1 as this would mean the calculation needs to go back an hour. Similarly, if your server was in California (GMT-8), you would write 8 and not -8 as this needs to go ahead in time, so to speak.

As all time zones (relative to GMT) are only different by either full or half hours, the offset is saved in the database (options.time_serv) in terms of hours and NOT seconds. If the difference is 3 and a half hours, it is stored as 3.5 and not 12600.