Date Difference

Create an application that can read in pairs of dates in the following format - DD MM YYYY, DD MM YYYY

Validate the input data, and compute the difference between the two dates in days.

Output of the application should be of the form - DD MM YYYY, DD MM YYYY, difference

Where the first date is the earliest, the second date is the latest and the difference is the number of days.

Input can be from a file, or from standard input, as the developer chooses.