pit stop calculator

I am in need of a pit stop calculator for vehicles, specifically cars. I have specific requirements I need this calculator to be able to calculate, so I am looking for someone to create a desktop application that can calculate these parameters with accuracy. The application will have the ability to be able to input two sets of data in order to calculate the differences between them, and come up with an accurate set of results based on the input provided. Accuracy is extremely important, as these results will be used in order to organize pitstop calculations during car racing events. The design should be modern, easy to use, and intuitive. This application needs to be the go-to pit stop calculator for race organizers, and for the end-user who desires an accurate calculation. The final product should be delivered within a reasonable timeframe, and should exceed all expectations.