Using Circular Reference to Schedule in Excel

[bobo999]

I am trying to solve a scheduling problem in excel.

What I have are dozens of Tasks similar to this output.

[TABLE="width: 685"]
<tbody>[TR]
[TD][/TD]
[TD]Saturday[/TD]
[TD]3-10-18 6:00 AM[/TD]
[TD]Sunday[/TD]
[TD]3-11-18 12:12 AM Length of task 18.3hours[/TD]
[/TR]
[TR]
[TD][/TD]
[TD]Saturday[/TD]
[TD]3-10-18 6:00 AM[/TD]
[TD]Sunday[/TD]
[TD]3-11-18 12:12 AM[/TD]
[/TR]
[TR]
[TD][/TD]
[TD]Saturday[/TD]
[TD]3-10-18 6:00 AM[/TD]
[TD]Sunday[/TD]
[TD]3-11-18 12:12 AM[/TD]
[/TR]
</tbody>[/TABLE]
Sunday

What I have are blocks of time that tasks cannot be run during, ie:
[TABLE="width: 343"]
<tbody>[TR]
[TD]Outage Start[/TD]
[TD]Outage End[/TD]
[/TR]
[TR]
[TD]3-9-18 12:00 PM[/TD]
[TD]3-10-18 10:00 AM[/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]3-12-18 12:00 PM[/TD]
[TD]3-12-18 9:00 PM[/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]3-13-18 12:00 PM[/TD]
[TD]3-13-18 11:00 PM[/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]3-14-18 12:00 PM[/TD]
[TD]3-14-18 11:00 PM[/TD]
[/TR]
[TR]
[TD][/TD]
[TD][/TD]
[/TR]
</tbody>[/TABLE]

What I am trying to do is calculate how the tasks overlap the windows where work cannot be done using sumproduct.
Q267 is task start and R268 is task end

 <outageend)*(r267><outageend)*(r267>SUMPRODUCT ( ( Q267 < outageend ) *  (  R267>=outagestart)  ) equals 1 (formatting is strange here)

<outageend)*(r267><outageend)*(r267><outageend)*(r267>
This seems to yield a binary yes task overlaps for one instance.

The concrete question I have, is I want to calculate using circular references or some other method, how much of my tasks overlaps those black out windows. Increment the task length by the overlap amount. Now the big question is of course, if after this increment, do I get pushed into another black out window, how many times will the circular reference iterate before the final solution. How can I achieve this?

The next step would be to calculate how much overlap there is, this is something I can't figure out. Following that, assuming circular reference iteration works as it should, I should be ok.</outageend)*(r267></outageend)*(r267></outageend)*(r267></outageend)*(r267></outageend)*(r267>