Quick, let me know. When you start counting numbers, do you start from one and end with 10, or do you start from zero and end with nine? I believe it is more common for us to say "one to 10" rather than "zero to nine". That's the convention I learnt in school and that's the convention we should stick with. Saying "zero to nine" is rather absurd because zero is not even a number. You cannot count anything that's not there and zero is simply not there. Correct me if I'm wrong.
Bringing this argument a step further, if "one to 10" is the correct convention to use, then "11 to 100" is also correct, as are also ranges of numbers like "101 to 1000" and "1001 to 2000". Then, the next 10 numbers would be "2001 to 2010".
Therefore, it is totally illogical and wrong that people are saying that the decade ended on 31 Dec 2009. Just because the calendar turned from 1999 to 2000 ten years ago did not mean that the 20th Century ended on 31 Dec 1999. It was partly because of the Y2K scare that computers would not work that made people believe wrongly that 2000 was indeed the turn of the century and millennium. On the contrary, the old millennium ended on 31 Dec 2000 and by extension, there is still one more year to go before the end of the first decade of the new millennium. This decade will only end on 31 Dec 2010. So perish the thought that we had reached the end of the decade at midnight yesterday. There are still 364 days to go.