@khurtwilliams I had a longer reply but just removed it because it was uncessarily long and might not have come across the way I wanted. The bottom line for me is that I personally think calendars are all arbitrary anyway, and can be changed and have been numerous times. If we as a people want to declare a decade like "the twenties" to be all the years the have a 2 in the tens place then that's fine. If that means someone wants to go back and declare that the first decade of the calendar is only 9 years long... well that's ok too. It's all arbitrary and made up by us, anyway.
Anyway, just my two cents. Happy New Year!