Cumulative/Running Total calculation with a condition

Hi all,

I hope you're all well.

I'm currently building a call centre report and one of the visuals is a "Total Open Calls" visual.

For this visual, I need to calculate the number of total open calls at the beginning of the new/current day n: 

1. All open calls have a status of 0, while closed is 100
2. At any given day, new calls come in and calls are close
3. The "Total Open Calls" calculation is:
   • All calls from all previous days (status=0) + new calls [day n-1] (status=0) - closed calls [day n-1] (status=100)

I need to showcase it in the image below:

I tried using the rolling total calculation and the results are only for the latest date. Whereas, the visual needs to showcase to date. 

Any help and tips will be greatly appreciated 🙂

Kind Regards,

Asa