It looks like a pretty silly problem but it's driving me mad.
The yearfrac function takes a two dates and a basis. Now assume basis = 1 ( Act / Act ) and two cases:
1) 06-Jan-06 -> 06-Jan-08 ( 730 days ) = 1.998175182 =>> divisor = 730/1.998175182 = 365.33333
2) 06-Jan-05 -> 06-Jan-07 ( 730 days ) = 2 =>> divisor = 730/2 = 365
In case 1) 2008 is a leap year ( but the "leap" has yet to come! ). Can anyone explain me the logic behind? I suppose the extra day is divided by 3 but where is the "Actuality" of the divisor?