CumulativePeriod aggregation, can't get this to filter properly

[PaalNavestad]

Hi I have a cumulative period aggregation. When I create an action from a dropdown box to a key value or a table to get the cumulative Month to date this works well. Also if i just a filter directly for a date it works. What i really want is not to have the dropdown but control the filter form the data. I have created a variable that is the date I want and otherwise missing. This does not give me the cumulative aggregation but the days value.

Do anybody have an idea why this should not work.

Pål N