Cumulative Count with Multiple Dates on Same Axis

Hello,

I am trying to figure how to create a cumulative count of my team's IT system testing over time - specifically broken out by the planned test dates and the actually executed test dates. I want to plot this as two different lines on the same axis of a line graph, and at the end of our software project the two lines should meet in the middle (where planned test date cumulative counts  = executed test date cumulative counts).

I understand the USERELATIONSHIP function, and have already created a reference Date table (see attached PBIX) to plot the planned and executed date cumulative counts together, and I understand how to create a cumulative count (using the date <=max(date) syntax), but I can't figure out how to create two measures, each of which  has a cumulative count of either planned or executed test dates AND has the USERELATIONSHIP function so that I can plot those two final measures on the same line chart as VALUES with the reference date table as my axis (images attached - the image labeled "Testing Timeline" is a mock example of what I am attempting, only I want the counts to be cumulative, not just counts per day of tests).

Thank you in advance for any help...it's much appreciated!!

https://www.dropbox.com/s/6r7qb861bxawigp/HTP%20TCER%20Dashboard.pbix?dl=0