Text Field showing different values depending on the calculation

Sorry about that, I just changed the field names.  I just have Start and Started.  Start is the assigned start date and started is when they actually started the project 

Can you please say the logic that you want in words and then I can convert that to a formula.  Please start with  7 days late and then 1 day late and then on time and then early and then not started to be sure to cover all time periods from late to early.

So I want a field that will tell me if a task has been started or not on time.  I want it to yield a result that will say "NA" if Active Dif Calc is equal to 0, and then if Active dif Calc is  less than 7 days but not equal to 1 it will say "L7".  And then if it is less than 1 day, it will say "L1".  Start and Started are both date/time fields.

And if possible, I want to add E1 if the difference between start and started dates are less than 24 hours.

I hope that makes sense.  I've been trying to figure this out but no luck