Javascript Date toDateInputValue()

// set today's date as new post date
Date.prototype.toDateInputValue = (function() {
    var local = new Date(this);
    local.setMinutes(this.getMinutes() - this.getTimezoneOffset());
    return local.toJSON().slice(0,10);
});//from ww w.j a v  a  2s.  com
var dateField = document.getElementById('date-picker');

console.log('hi');

// Gets today's date and corrects for timezone
// Use in the date picker input for default value (today)
Date.prototype.toDateInputValue = (function() {
  var local = new Date(this);
  local.setMinutes(this.getMinutes() - this.getTimezoneOffset());
  return local.toJSON().slice(0,10);
});/*from  w w w  .  j a  va2  s.co  m*/