
Frac Addinfrac.xla is an Excel '97 addin containing a function called Frac() that calculates the fraction of the year. Download the zipped file AddIns.zip. The function has two arguments =Frac( OfDate , [Places] )
The Frac function is the 365 day calendar of decimals the every actuary uses. Each month equals 1/12th of the year. Then each day in that month is 1/(no of days in month) of the 1/12th. Examples
Notice that the function takes into account leap years. The program has been checked against other programs, but you are encouraged to check it yourself before relying on it. It is complimentary from us, Dean & Company, to anyone interested. 
If you have questions or comments, please contact us at Dean & Company. 