问题
I am trying to find a way to COUNTIF(S) between a certain set of dates, but only get the count of the unique dates. For context, I am tracking meters over days. I can get more than one instance on the same day with differing meter values. The fact that can happen is screwing up my meters/day average.
Data!A3:A8700 - is the date range.
I am summarizing things monthly, so, in this case, for this example, I'd like something that:
1) Uses COUNTIF (or anything that will work!) between date x and date y. Would like X and Y stored to be pulled from DATA!A3:A8700. In this case, for instance, 11/1/2014 = x and 11/31/2014 = y
2) I would ONLY like to get unique dates as a valid part of the count:
11/1/2014
11/2/2014
11/2/2014
11/3/2014
Would return 3, for instance, not 4.
I have found solutions to get unique numbers in the entire column, but nothing yet for a range within that column. Or, more accurately, I have not been able to figure out how to properly modify those.
回答1:
As far as I understand, you want the following, tell me if I am wrong:
That is, starting from 01/11/2014 that is in D1 and ending in 12/11/2014 that is in D2, you want to calculate unique dates that fall inbetween these two dates in your A1:A100 range.
And in this example, there are 6 unique dates, as shown in result cell D4. Here is the formula to count unique values (dates) in column containing a series of dates.
the formula:
=SUM(IF(FREQUENCY(IF($A$1:$A$97>=D$1;IF($A$1:$A$97<=D$2;IF($A$1:$A$97<>"";MATCH($A$1:$A$97;$A$1:$A$97;0))));ROW($A$1:$A$97)-ROW($A$1)+1);1))
you may need to adjust it according to your regional settings, by replacing ";" with ",".
here is the example excel sheet to download from dropbox.
来源：https://stackoverflow.com/questions/27021006/countif-unique-dates-between-a-range