SCD1 and power pivot

I have a table that looks like this

person  stage1  stage2  stage3

1              jan       mar     jun

2             jan        april    july

I can measure the number of people in a given stage on a given date like this

stage1count = calculate(counta([person]),filter(all(stage1,stage2,stage2),fakedate>stage1&&fakedate<stage2)))

stage2count = calculate(counta([person]),filter(all(stage1,stage2,stage2),fakedate>stage2&&fakedate<stage3)))

where fakedate is the max date of the filter context date.  If you assume that stage 1,2,3 always succeed the prior state.

Then I can do a table like

           jan feb mar april may june july

stage1 2     2     1     0      0      0     0

stage2 0    0      1     2      2      1     0

stage3 0    0      0     0     0       1     2

Of course, this can't be how excel was designed because then I'd have to make measures for every single scd1 measure I've got and then Id' never be able to pivot, explode and implode.  How do I make a column value in the underlying rows change value based on the filter context.  I need something like if([date from filter context]<stage1,stage1,if ... so that I can just drag that new colunm in to the pivot and pivot accordingly without having to machine every measure.