why doesnt the earlier function work when used within my calculation

Rolling Sum = 

var object_1 = Calculate(SUM('Table 1'[Value]),
   Filter(allselected('Table 1'),
      COUNTROWS(FILTER('Table 1',
         EARLIER('Table 1'[Date])<= 'Table 1'[Date]))))

var object_2 = Calculate(SUM('Table 2'[Value]),
   Filter(allselected('Table 2'),
      COUNTROWS(FILTER('Table 2',
         EARLIER('Table 2'[Date])<= 'Table 2'[Date]))))

return

calculate(object_1 - object_2,
   Filter(allselected('Date Table'),
      COUNTROWS(FILTER('Date 2',
         EARLIER('Date Table'[Date])<= 'Date Table'[Date]))))

I am trying to create a rolling sum from the results of a calculation between two values (object_1 and object_2). The problem is when i try to achieve this by using the calculate function + the earlier function, it doesn't seem to have any affect.

I have tried creating a virtual table with the values i am trying to create a rolling sum out of (using Summarize), then using earlier in a Sumx function to create the desired effect but this did not work.