To set the record straight, there *is* a difference between GMT Time (now known as UTC or Universal Co-ordinated Time) and British Local Time. GMT (UTC) is based on Greenwich in England and is a world wide time scale. All countries are either East or West  (+ or -)of Greenwich (except for Britain itself of course) and thus all one needs to know is how many hours + or - GMT (UTC) their country is and whether their particular country is on Daylight Time. No more trying to figure out if a particular part of the world is on Daylight Time as well as your own and then calculating the differences. Using the charts below, it only takes a few seconds to make the calculations and, once you've done it a few times, no need to do it ever again 

So: Should I wish to find out what time it is in Canada when it is 8 pm in #magicisle for the kiwis, I tick the 'C' square and  the 'N' square below, then hit, 'get times'. 
I find that target time (NZ) is twelve hours ahead of GMT so I subtract those twelve hours and find that GMT it will be 8 am of the same day (Monday) Canada - supposing I am looking at -7 hours on the Pacific - will be seven hours less than that.. 1:00 am Monday when all good Canadians might well be sleeping and all good Germans are at work. 

Which leads me to wonder yet again about the merits of having a 2 pm Sunday preview - that would allow the Canadians among us to come in at a relatively respectable hour. Let me know what you think. 

View the time difference between UTC and selected countries.

Facilities provided by and Copyright ©Time Service Dept., U.S. Naval Observatory, Washington, DC.
Used with permission.