Thanks Alex, for getting back with me.
Sorry I didnt post back sooner, I was out of town.

To elaborate, for each inspection entered into my database there is a window that the maintenance can be performed. So I need to figure out two things
1. how long until its due
2. do not exceed time.

an example

1. A 30hr inspection would be calculated something like this.
            
A. The ACFT Hours(1002) subtracted from the Due at hours(1030hrs) would equal my due in time of (28hrs)

B. My DoNotExceed time would be calculated by 10% of the inspection interval(30hrs)added to the Due time(28hrs) would equal (31hrs)

This would be simple if I were only dealing with just one type of inspection. But my delema is I have several different types.

The end result is to have this displayed on a form that would maxamized to a flatpanel for maintenance personnel to look at.    

Hope this helps clarify what i am trying to accomplish.

Thanks again, Gary