UTCDate as a subclass of Date

UTCDate.js

function UTCDate(a) {
  var x;
  switch (arguments.length) {
    case 0:
      x = new Date();
      break;
    case 1:
      x = (typeof a === 'number') ? new Date(a) : new Date(Date.parse(a));
      break;
    default:
      x = new Date(Date.UTC.apply(Date, arguments));
  }
  x.__proto__ = UTCDate.prototype;
  return x;
}

UTCDate.prototype.__proto__ = Date.prototype;
UTCDate.prototype.getDate = Date.prototype.getUTCDate;
UTCDate.prototype.getDay = Date.prototype.getUTCDay;
UTCDate.prototype.getFullYear = Date.prototype.getUTCFullYear;
UTCDate.prototype.getHours = Date.prototype.getUTCHours;
UTCDate.prototype.getMilliseconds = Date.prototype.getUTCMilliseconds;
UTCDate.prototype.getMinutes = Date.prototype.getUTCMinutes;
UTCDate.prototype.getMonth = Date.prototype.getUTCMonth;
UTCDate.prototype.getSeconds = Date.prototype.getUTCSeconds;
UTCDate.prototype.setDate = Date.prototype.setUTCDate;
UTCDate.prototype.setFullYear = Date.prototype.setUTCFullYear;
UTCDate.prototype.setHours = Date.prototype.setUTCHours;
UTCDate.prototype.setMilliseconds = Date.prototype.setUTCMilliseconds;
UTCDate.prototype.setMinutes = Date.prototype.setUTCMinutes;
UTCDate.prototype.setMonth = Date.prototype.setUTCMonth;
UTCDate.prototype.setSeconds = Date.prototype.setUTCSeconds;
UTCDate.prototype.toString = Date.prototype.toUTCString;

UTCDate.prototype.toDateString = function() {
  var parts = this.toUTCString().split(' ');
  return parts[0].slice(0, -1) + ' ' + parts[2] + ' ' + parts[1] + ' ' + parts[3];
};

UTCDate.prototype.toTimeString = function() {
  var parts = this.toUTCString().split(' ');
  return parts[4] + ' ' + parts[5];
};