aggr in set analysis

[#1]

Hi,

I want to sum the sales of the last day of each month. I cannot use an end of month flag because the calculation needs to be flexible so if the user chooses 5,6,7,8,9th the last day of month should be the 9th.

So I am trying with aggr in set analysis but it does not work so I figured I am doing something wrong.

SUM({$<Date = {"=Date=Aggr(nodistinct $(=MaxString(Date)),MonthYear)"} >} Sales

) - Gives nothing

SUM({$<Date = {"=Aggr(nodistinct $(=MaxString(Date)),MonthYear)"} >} Sales

) - Gives me the the total sum of all days for each month, which is not what I am after.

Any ideas?

Kind regards

Peter