Calculate Date Difference

Hi Dears,
I request a help:
A1 = 01-Apr-2009
B1 = 02-Apr-2009
C1 = 03-Apr-2009
D1 = Blank
E1 = 05-Apr-2009
F1 = 06-Apr-2009

What is the best suitable formula to find "First blank cell", then "date difference" between today and its previous cell's (i.e today minus "C1" in this case).

Thanks & Best regards,
Ananthakrishnan.K