changing_date_format.js

export function getDayOfWeek(date) {
  const dayOfWeek = new Date(date).getDay();
  return isNaN(dayOfWeek) ? null : ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'][dayOfWeek];
}

export function getMonthName(date) {
  const monthNumer = new Date(date).getMonth();
  return isNaN(monthNumer) ? null : ['January', 'February', 'March', 'April', 'May', 'June', 
    'July', 'August', 'September', 'October', 'November', 'December'][monthNumer];
}

var timestamp = 1511637943345;
var date = new Date(timestamp);
var hour = timestampDate.getHours();
var minutes = timestampDate.getMinutes();
var seconds = timestampDate.getSeconds();

//target output is Saturday, November 25, 2017, 16:25:43
console.log(`${getDayOfWeek(date)}, ${getMonthName(date)} ${date.getDay()}, ${date.getFullYear()}, ${hour}:${minutes}:${seconds}`);