Corrected, based on birthdays in september 15th
Pasi, it's the player's age as of September 15th, 2010. If their birthday comes earlier in the year than that, you count this year. If it comes later than that, you count last year.
So:
Steve Bernier born march 31st in 1985, will be
25yrs old on September 15th
Mike Brodeur born march 30th in 1983, will be
27yrs old on september 15th
John Scott born september 26th in 1982, will be
27yrs old on september 15th
Brian Boyle born december 18th in 1984, will be
25yrs old on september 15th
Chris Osgood born november 26th in 1972, will be
37yrs old on september 15th
Drew Stafford born october 30th in 1985, will be
24yrs old on september 15th
Niklas Hagman born december 5th in 1979, will be
30yrs old on september 15th
Note that all of this may be moot if we go to the updated sim, which includes specific player birthdays.