If these are set as a row field it will only show the unique dates, you
could COUNTA the total rows or just see where they end up and deduct from
where they start
Add a column next to your original Dates column,
named CountD and enter this array formula:
=1/COUNTIF(Dates,Dates)
Include CountD in your PT as Sum of CountD
The Grand Total for Columns in your PT will show
the number of unique Dates in ROW.