Use countif to count unique values?

[bam]

Hello, is there a way to count unique values in a list of values.
Specifically, I have many 200 rows with specific dates. 1/1/2007, 3/12/2007,
etc. and I want to count the unique instances of dates.

Any help appreciated

Thanks

bmac

 

[Barb Reinhardt]

Add a helper column with this in it.

B1: =countif($A$1:$A1:A1)

Copy down. Let's assume you copy to B100.

In B102, put this: =countif(B1:B100,1)

It's not elegant, but I think it gets you what you want.

 

[T. Valko]

Try this:

=COUNT(1/FREQUENCY(A1:A200,A1:A200))

Biff

 

[Bernd]

Hello,

Or
= SUM(SIGN(FREQUENCY(A1:A200,A1:A200)))

Regards,
Bernd