Working on a time sheet I need to deduct cell(a1)- start time from cell(b1) -
end time plus another 30 minutes - lunch time (TIME(0,30,0)? But I need
nested if statements also as in:

if (endTime - startTime <4hrs, endTime - startTime,if(endTime -
startTime4hrs, (endTime - startTime) - 30mins, if((endTime - startTime) -
30mins8hrs, 8hrs)))

This might not appear to make sense but it does because surplus hours will
be in another cell to be calculated at a different rate.

I have been doing this just with numbers, but it gets awkward taking away
the 30 minutes as in ((16.30 - 08.00)-0.30) = 8, (correct),but, ((16:30 -
08.30)-0.30) = 7.7 (because it's time represented by a number it should be
7.5, or if time 7.30)

There must be a simple way round this isn't there?