function userAdjust() in Language.php handled user time zone not correct. This affect time zone with clock shifts, for example "Europe/Berlin".
For example: in summer the winter time is not corrected displayed (and the other way round).
set the time zone in preferences to "Europe/Berlin" (on de.wp). For logged out user and the option 'server default' the time is correct!
After setting the preferences:
the header of version http://de.wikipedia.org/w/index.php?oldid=52264210 show 14:01, 26. Okt. 2008, the included REVISIONTIMESTAMP says 20081026150115 (that was after clock shifts, winter time has an offset from 1 hour to the current summer time) => not equal, offset from 1 hour
the header of version http://de.wikipedia.org/w/index.php?oldid=52230987 show 18:14, 25. Okt. 2008 (summer time, same as current time), REVISIONTIMESTAMP says 20081025181428 => equal
A solution can be: Use wfTimestamp( current user timezone, $date ) to create the adjust time. Use wfTimestamp( TS_MW, $date ) to adjust the server default. Use mktime() if the offset is specify by user.
I am not so familiar with php and mediawiki, so I cannot give you a patch, only this description and idea. I hope, I am on the right lines with it. Thanks.
Version: unspecified
Severity: enhancement
URL: http://de.wikipedia.org/w/index.php?title=Hilfe:Variablen&offset=20081027000000&action=history&limit=2