I have this problem of reprogramming my brain for the new year roll-over.
In my days of creating memo's to the files at Accenture, it took months for me to get the date correct. I discovered how confusing this could be during a deposition, when a lawyer challenged me on a memo that I had written a year before the event. He knew I had mis-dated the memo but he wanted to confuse me with the hopes of digging something up. One hour into the deposition, I finally figured out that I had mis-dated the memo - pointed this out to him. He just smiled and said - "I know". Those lawyers - sneaky fellows :)
Calendars are fairly arbitrary - there is the Gregorian, Julian, Islamic, Hebrew, Persian, Hindu, Chinese, Lunar, Solar .... the list goes on. I have been watching the History Channel DVD's on "Rome Rise and Fall of an Empire. Like all conquering nations our calendar is a result of Gaius Julius Caesar (the month of July is named because of his birthday - July 13 100BC).
Just imagine the stress in your life if suddenly a conquering nation decided to change the calendar - Birthdays, New Years, Holidays etc. A year end roll-over would be the least of your concerns.
Since it takes me months for the actual change Year End roll over - maybe I like the Chinese system - Feb 14 is when 2010 begins.