I'm in the U.S., we usually end around mid-may and go back first week or two of August. we did go into June this year because we had two snowstorms, which added two weeks of make-up days to the year, which sucked.
In the U.S. different states, or even different counties, start at different times. I'm in Kentucky, we start early August and end mid-may, while others start in September and end in June.
arghh