counting unique values

[D-Spark]

I have the following:

=COUNTIF(Sheet1!I3:I10,B4)

where B4 is a date and I3:I10 is a list of dates

to the above I want to introduce a method to uniquely count occurances in Sheet1 range A3:A10 but when there is also a match in range I3:I10 to B4

 

[DonkeyOte]

can you clarify with an example ?

ie what is listed in A3:A10

 

[Aladin Akyurek]

Control+shift+enter, not just enter...

=SUM(IF(FREQUENCY(IF($A$3:$A$10<>"",
    IF($I$3:$I$10 =B4,MATCH("~"&$A$3:$A$10,$A$3:$A$10&"",0))),
      ROW($A$3:$A$10)-ROW($A$3)+1),1))

I have the following:

=COUNTIF(Sheet1!I3:I10,B4)

where B4 is a date and I3:I10 is a list of dates

to the above I want to introduce a method to uniquely count occurances in Sheet1 range A3:A10 but when there is also a match in range I3:I10 to B4