title: C# iterate backwards over date
body: <p>I am looking for a C# solution that will allow me to iterate backwards over a date.
  Starting at the current date or provided date I would like to loop over the date subtracting one day each time through the loop for a given number of days.  It should of course be able to detect when the month has changed or it is a leap year etc., and return the date in MM-DD-YYYY format.</p>