Calculating flagged/blocked days from Working Days

I have defined a Cycle on import for one of my projects… let’s say ProjectX.

I’m using ‘ProjectX Workdays’ to show the total number of days tickets were in my Cycle during a qauarter period.

I would now like to show how many of those days (total time) that tickets were flagged (blocked), from the days in the above measure.

I tried the following which does return some data but I don’t think it includes all flagged time so may have got this wrong?

(
[Measures].[ProjectX workdays],
[Flagged].[Impediment]
)