The problem: A function is to be run every (day) between two dates, deciding whether an action stops on that day. The probability of the action stopping on any day should be as similar to that of any of the others as possible.
This doesn't work: ( 1/(numberOfDays) )
This distribution is even less flat: ( dayNumber / numberOfDays )
This is the way to do it: ( 1/(numberOfDays - dayNumber) )