Currently GMT(Zulu) is 09:23. BUT the whole of the northernm hemi is (I assume) on Summer time and so +1; Current UK time is 10:23; CET is CURRENT UK plus 1; so it's currently 11:23 in Valencia.
GMT never changes; local time; where daylight saving, or summer time is used may.
Simon, you have to check which day you are on overthere in the UK but we are definitely NOT on summer time! Current time in Valencia right now is GMT+1: 11:31 http://wwp.greenwichmeantime.com/
