Pseudo Code

Add or Subtract hours and/or minutes

Enter first hours and minutes "From:"

Enter second hours and minutes below "From:"

When you subtract, the greater number of hours and minutes should be entered first.

Select add or subtract.

The hours entered must be a positive number or zero (0).

The minutes entered must be a positive number or zero (0).

Click "Click to Calculate" button. The total will appear.

Trying to figure out a pseudo code for a time clock algorithm that takes a start tiime and an end time and calculates the days total time worked. then round to the nearest quarter hour 

If a greater number of hours and minutes is subtracted from a lesser number of hours and minutes the result will be erroneous.

NaN = not a number