Calculate based on certain Date criteria similar to previous month

[v_mark]

Good day,

Been struggling to figure out what is the best way to calculate these.
 

Begin Inv : the count of open items to start the specific month

  Closure: the number of items closed in the specific month

What I want to have is a measure that will calculate any placement that is open on Jan 1st of 2021.

Which considered as the begin inventory for the start of the month and if the close date is =<12-31-2020 (for example)  it would not count. 

What I have so far: Begin Inventory # = CALCULATE(COUNTROWS('sample'),'sample'[Status] = "Open")

and another calculation that would determine how many were closed in a month eg. 01-01-2021 to 01-31-2021.

which I believe I was able to do so by doing. 

 Closure: CALCULATE(COUNTROWS('sample'),'sample'[Status] = "Closed" )

 Please see the pbix file here 

[amitchandak]

@v_mark , refer if approach of this blog can help

https://community.powerbi.com/t5/Community-Blog/HR-Analytics-Active-Employee-Hire-and-Termination-tr...

[v_mark]

If Jan 1st an example, As far begin inventory is concern what I am hoping to get is to count all the open items <= 12/31/2021

like for Feb 1st count all the open items <=01/31/2021 and goes on

Which talks about ONLY the last day of the previous month and put it on a table