Here is how my world figures GMT
NY is east coast usa and that is GMT -5.00 hours.

GMT +10 would be australia, vlidivostok rushka, or guam.

If yo are posting at some odd hour (4AM for instance) then GMT is 9AM (GMT - 5 hours = your time, or your time +5 hours = GMT)

if you can figure this out, you'll know where in the world it is 5 pm so you'll know it is beer time somewhere all the time. and if you dring enough beer, you won't care.