count time after midnight

This is a follow up to another thread of same name.

=(($a1<=BR$4)+($b1>BR$4)+($a1>$b1)=2)+0

so If a1 = 18:00 and B1 = 02:30 then 19:00 or 01:00 in BR4 will give a 1 but 03:00 will give a zero, is that what you need?

Of course the formula still works if your shift doesn't pass through midnight....

I was not able to get the formula to work as previously described, but perhaps I am not looking at it correctly. I have attached a sample workbook of what I am trying to accomplish and would appreciate some tweaking of the formula.
The formula works for shifts between 0000 and 2400 but does not when crossing over midnight.
I would also like to understand the logic behind the formula. I know it has to do with T/F conditions, but I'm confused about the "2" in the formula.

Thanks,
TC