Formula For Date Counting

I have a column with dates in it. Example "04/04/2007" don't know if format will matter that is why I am showning an example.

I need a formula that looks at that column and tells me how many days were entered for a month. I thought a pivot table would work well but the same date could be entered many times and that would skew the number of days counted. The final result is a table that had each month with the number of days entered. Keep in mind that I only want each day counted once even though it may have been entered 5 times.