      *  If the receiver is earlier than the provided date, the returned value will be negative.
      *
      *  @param date     Date - The provided date for comparison
-     *  @param calendar NSCalendar - The calendar to be used in the calculation
-     *
-     *  @return Int - The Int representation of the years between receiver and provided date
+     *  @param calendar Calendar? - The calendar to be used in the calculation
+     *
+     *  @return Int - The years between receiver and provided date
      */
     func years(from date: Date, calendar: Calendar?) -> Int {
         var calendarCopy = calendar

     *  If the receiver is earlier than the provided date, the returned value will be negative.
     *
     *  @param date     Date - The provided date for comparison
     *  @param calendar NSCalendar - The calendar to be used in the calculation
     *
     *  @return Int - The Int representation of the days between receiver and provided date
     */
    func days(from date: Date, calendar: Calendar?) -> Int {
        var calendarCopy = calendar

     *  If the receiver is earlier than the provided date, the returned value will be negative.
     *
     *  @param date     Date - The provided date for comparison
     *  @param calendar Calendar? - The calendar to be used in the calculation
     *
     *  @return Int - The weeks between receiver and provided date
     */
    func weeks(from date: Date, calendar: Calendar?) -> Int{
        var calendarCopy = calendar
