That isn't quite the social definition
My experience is that people often refer to the next decade or 2 in the short form as well. For instance in the 80's I am sure I said at some point, "I wonder what will happen in the 90's?"
It is somewhat complicated by the fact that our century rolled over not long ago, and English doesn't have good names for the 00's and 10's. (People aren't really calling this decade anything, and the next one will be the "teens".) But in 10-15 years, people will say "20's" and mean the future.
Cheers,
Ben
