Transform year, month and day to an Excel serial date
[C++]
int XlDateToSerial(
   double* date,
   int yy,
   int mm,
   int dd
);
Pointer to a variable which will be filled with a serial date value (as used by Excel).
Year (eg 1996).
Month (1-12).
Day of month (1-31).
1 if the function succeeds; 0 if it fails
This function calls Excel's DATE() function
			to calculate a serial date from its components. Because it uses Excel for the transformation, it handles variations in 
			the Excel base date transparently.
Header: xlldate.h