This seems to work. The +1 is for the GMT+1, not because of $daylight setting.

Code:
//echo -a $gmt( $calc($ctime($replace(2013-01-10T13:13:13Z,t,$chr(32),z,$chr(32))) - $timezone +1*3600),dd.mm.yyyy HH:nn:ss)


Since your example used an old date, beware that certain date ranges may be off prior to 2006 due to assuming the current rules were in effect then.

https://forums.mirc.com/ubbthreads.php/topics/264232/$asctime_daylight_rules#Post264232