How to make counts in between dates?

Hi guys,

So, I've got this thing that I just can't make to work. Basically, I have a bunch of data a windmill park which is under establishment.
The thing is that the windturbines undergo to stages called "commissioning" (when its being built and tested) and "commercial operation" (when its finished and ready to use).

I need to get a daily ratio between the number of mills in commissioning and commercial operation. But to do that, I need to get the amount of mills being in either category each day.

I figured out that I maybe could solve the challenge by using the COUNTIF formula, but it doesnt seem to catch all the criteria since a mill is in commiosing in between two days (between the day it began its commissioning and the day it ended it/or still going).

Here's an idea of how the data looks like. Its pretty straightforward information wise.

Any ideas?

idea.JPG