You can accomplish this with MMYYYY data by creating an aggregated column using a periodic operator. The text from of the expression would be this, if Expenses is the measure and Date is the MMYYYY data item. RelativePeriod(_Sum_, 'Expenses'n, 'Date'n, _ByMonth_, -1, _Full_, {Date}) You cannot accomplish this in Designer at the Day level--only year and month.