Function NombreDeBissextesEntre%(a As Date, b As Date)
'Cherche le nombre de bissextes dans l'intervalle [a,b], (a<=b).
Dim l%
For l = Year(a) - (a >= DateSerial(Year(a), 3, 1)) To Year(b) + (b <= DateSerial(Year(b), 2, 28))
NombreDeBissextesEntre = NombreDeBissextesEntre - (Day(DateSerial(l, 3, 0)) = 29)
Next
End Function