add timezone offset to date javascript code example

Example 1: client timezone offset in JavaScript

var clientTimezoneOffset = new Date().getTimezoneOffset()/60;//offset in hours

Example 2: get browser timezone javascript

Intl.DateTimeFormat().resolvedOptions().timeZone

Example 3: javascript date timezone

// this example takes 2 seconds to run
const start = Date.now();

console.log('starting timer...');
// expected output: starting timer...

setTimeout(() => {
  const millis = Date.now() - start;

  console.log(`seconds elapsed = ${Math.floor(millis/1000)}`);
  // expected output : seconds elapsed = 2
}, 2000);