Heathen, if you look on the label on the end of your box to the right of your searial number below the product number you will find a number like 9068 this number is the manufactur date,to break it down the first number or two is the year with the last three being the day of the year.So with 9068 it would be 2009 on the 68th day(March 8th 2009.)
Another one I have handy is 0361 or 2010 on the 361st day (December 27,2010.)
I hope this helps. Good Luck.