Javascript Date isValid()

// http://stackoverflow.com/questions/1353684/detecting-an-invalid-date-date-instance-in-javascript
Date.prototype.isValid = function () {
    return this.getTime() === this.getTime();
}

Date.prototype.isValid = function() {
  return this.getTime() === this.getTime();
};

function twoDigits(value) {
  if (value < 10) {
    return '0' + value;
  }/*from  w w w .j av a2  s.co  m*/
  return value;
}

exports.getMyDate = function(timestamp) {
  var date = new Date(timestamp * 1000);

  return date.getFullYear()
    + '-' + date.getMonth()
    + '-' + date.getDate();
}

exports.time = function() {
  var date = new Date();

  return date.valueOf() / 1000;
}

Date.prototype.isValid = function () {
    return this.getTime() === this.getTime();
};