Get Eastern Standard Time

JavaScript

// ===================================================================
// Returns the calculated the offset time from UTC
// This allow us to get the EST datetime from any timestamp
// ===================================================================
function calcTime(d) {

	// Eastern Time Zone is behind Coordinated Universal Time by 5 hours
  var offset = '-5';

  // create Date object for current location
  // or if we pass in a date use that
  if (!d) {
    d = new Date();
  }

  // convert to msec
  // add local time zone offset 
  // get UTC time in msec
  var utc = d.getTime() + (d.getTimezoneOffset() * 60000);

  // create new Date object for different location
  // using supplied offset
  var nd = new Date(utc + (3600000 * offset));

  // return time as a string
  return nd.toLocaleString();

}

// ===================================================================
// Current Time
// ===================================================================
var currentTime = new Date();
console.log(currentTime);
console.log('Current Time: ' + calcTime(currentTime) + ' EST');

// ===================================================================
// Custom Time
// ===================================================================
var customTime = new Date('2015-02-12T19:16:07.000Z');
console.log(customTime);
console.log('Custom Time: ' + calcTime(customTime) + ' EST');

var customTime1 = new Date('2016-09-16T14:33:45.75Z');
console.log(customTime1);
console.log('Custom Time1: ' + calcTime(customTime1) + ' EST');