I have used this formula:

=(NETWORKDAYS(D14,E14-1)*8+(MOD(E14,1)-MOD(D14,1))) to calc the time between
start and stop considering an 8 hr business day.

the problem is that i am getting a negative if the start and stop is in the
same day.

I have also tried to add a *24 at the end still no good.

What am i doing wrong?