Distinct count Measure (This Year vs Last Year - incomplete year)

[jeancake]

I'm trying to compute a distinct count of accounts this year vs last year. My transaction data is from 1/1/2019 through 9/30/2020. The distinct count is easy for 2020, but when I try to create a measure using SamePeriodLastYear I'm getting the full year distinct count for 2019, but I need it through 9/30/2019. Can someone help with the proper syntax for this measure?

Thanks in advance.

 

[ExcelGzh]

jeancake

I don't know if you're using vba or cell functions, but if you were using cell functions it would go something like this:

If the last date for 2020 was in say cell E100 and the dates for 2019 were in say column H, then if you used COUNTIF(H:H,"<="&DATE(YEAR(E100)-1,MONTH(E100),DAY(E100))) then that would count the number of rows in column H that had dates that were less than or equal to today's date a year ago.