Counts unique values per dates

Hi,

Array formula (important that you know how to enter this type of formula in Excel) in D2 and copy across:

=SUM(--(FREQUENCY(IF($B$2:$B$13=D1,$A$2:$A$13),IF($B$2:$B$13=D1,$A$2:$A$13))>0))

Regards

Please try this file as well.