In Qlikview(version: 12.20 November 2017) I have a formula that calculates the sum of values for the past year, when selecting from the filters a year and a month, according to the selection the sum is calculated for the last 12 months. (Example: if December 2021 is selected, then sum is calculated from January to December 2021).

The formula doesn’t work however, when the selected month doesn’t have any data, the sum returns as 0, even if there are data for other months.