small-extension.js

!function() {
  var DATE_EXT = {};

  var extendMe;

  DATE_EXT.getLabel = (function() {
    return function() {
      if( isNaN( this.getTime() ) ) return NaN;

      return (this.getMonth() + 1) + '/' + this.getDate() + '/' + this.getFullYear().toString().substr(2,2);
    };
  })();

  DATE_EXT.getDelta = (function() {
    return function(deltaDate) {
      if( typeof deltaDate == "string" ) deltaDate = new Date(deltaDate);
      if( !this.isDate() || !deltaDate.isDate() ) return false;
      
      // Get # of milliseconds between dates
      var delta = this.getTime() > deltaDate.getTime() ?
                          this.getTime() - deltaDate.getTime() :
                          deltaDate.getTime() - this.getTime();

      // Set up some helper methods
      var toSecond = function(d) { return Math.floor( d / 1000 ); }
        , secondToMilli = function(d) { return d * 1000; }

        , toMinute = function(d) { return Math.floor( d / 1000 / 60 ); } 
        , minuteToMilli = function(d) { return d * 1000 * 60; }

        , toHour = function(d) { return Math.floor( d / 1000 / 60 / 60 ); }
        , hourToMilli = function(d) { return d * 1000 * 60 * 60; }

        , toDay = function(d) { return Math.floor( d / 1000 / 60 / 60 / 24 ); }
        , dayToMilli = function(d) { return d * 1000 * 60 * 60 * 24; };

      // Calculate Days and remove from total delta
      var dayDelta = toDay( delta );
      delta -= dayToMilli( dayDelta );

      // Calculate hours, remove from total again
      var hourDelta = toHour( delta );
      delta -= hourToMilli( hourDelta );

      // Calculate minutes
      var minuteDelta = toMinute( delta );
      delta -= minuteToMilli( minuteDelta );

      // And seconds
      var secondDelta = toSecond( delta );
      delta -= secondToMilli( secondDelta );
      // Leftover delta === millisecond time delta

      // Return that shit!
      return {
        "days" : dayDelta,
        "hours" : hourDelta,
        "minutes" : minuteDelta,
        "seconds" : secondDelta,
        "milliseconds" : delta
      };
    };
  })();

  if (Object.defineProperty) {

    extendMe = function(nativeObj, extensions) {
      for (var extension in extensions) {
        Object.defineProperty( nativeObj.prototype, extension, {
          configurable  : true,
          writable      : true,
          enumerable    : false,
          value         : extensions[extension]
        });
      }
    };

  } else {

    extendMe = function(nativeObj, extensions) {
      for (var extension in extensions) {
        obj.prototype[extension] = extensions[extension];
      }
    };
  }

  extendMe(Date, DATE_EXT);
}();