My friend Rick has a major pet peeve that’s only making him madder in this final week of 2009: everyone’s continued misuse of the term decade, as in “the top _______ of the decade.”
As Rick correctly points out, the end of 2009 is not the end of this decade: next December 31 will officially end the decade. This is because the very first decade included years 1 AD through 10 AD. Year 11 was the second decade of the millenium, just as 2011 will be the first year of the second decade of this current millenium in which we find ourselves.
It could always be argued, of course, that a decade could be any set of ten consecutive years, so it’s entirely possible that toward the end of 2011, for example, we might talk about the biggest homeland security advances within the decade since September 11th.
But it doesn’t appear that most usages of decade are really using this kind of logic.
So for Rick’s sake, please get it right. And have a happy final year of the current decade!