On Mon, 17 Aug 2009 15:12:07 -0400, Ron Rosenfeld
wrote:

=SUMPRODUCT(--(WEEKDAY(ROW(INDIRECT(MIN(Rng)&":"&MAX(Rng))))=DOW ))

Rng is your column of dates (e.g. $A$4:$A$400)

DOW is the day of the week in which you are interested
1=Sunday
2=Monday
etc.

I forgot to add that for MIN(Rng) and MAX(Rng) you can substitute dates (or
cell references containing dates), representing the Start and End date that you
might want to consider for analysis.

If you just want to analyze the entire column, then the entire
ROW(INDIRECT(...)) can be replaced merely by Rng.

e.g.: =SUMPRODUCT(--(WEEKDAY(Rng)=DOW))
--ron