Calculates the fraction of the year represented by the number of whole days between two dates (the start_date and the end_date). Use the YEARFRAC worksheet function to identify the proportion of a whole year's benefits or obligations to assign to a specific term.

'Declaration
 
Public Class CalcYearFracFunction 
   Inherits CalcBuiltinFunction

'Usage
 
Dim instance As CalcYearFracFunction

public class CalcYearFracFunction : CalcBuiltinFunction