Calculating Effective headcount

Hello Experts,

I am trying to create a Headount/FTE dashboard. I have employee records like below table. I have also added a calendar table for time slicer. Everything works great. Thanks to this wonderful forum. I came here whenever stuck and plenty of previous similar problems/solutions to refer to.

I wanted to further extend this dashboard to be used as a tool for heacount/FTE forecast. I am trying to calculate effective headcount for this purpose. I mean when I am calculating effective headoucnt for the month of say Feb'21, employee ID YYYY0002 should be counted as 0.5 instead of 1 as the employee has joined in the middle of the month. 

The Summary HC table should look like below:

I am using below measure to get headcount numbers successfully. However, stuck at effective headcount calculation. Should I use Measures or add custom columns!

CALCULATE(DISTINCTCOUNT('Employee_Table'[Emp ID]),FILTER(ALL('Calendar'[Date]),[Min Date]=[Min Date]),'Employee_Table'[Joining Date]<MIN('Calendar'[Date]))

I tried below measure to get employee level effective headcount number. This seems wrong because of the way I am trying to get employee level Exit/Joining date. It's actually giving Min/Max date from column, can be for any employee. How do I get employee level Exit/Joining Date!

(MIN(MIN('Employee_Table'[Exit Date]),MAX('Calendar'[Date]))-MAX(MIN('Employee_Table'[Joining Date]),MIN('Calendar'[Date])))/(MAX('Calendar'[Date])-MIN('Calendar'[Date])+1)

Thanks