Using countries and timezones npm package:

import {getTimezone} from 'countries-and-timezones';
const australianTimezone = 'Australia/Melbourne';
console.log(getTimezone(australianTimezone));

Using countries and timezones npm package:

import {getTimezone} from 'countries-and-timezones';
const australianTimezone = 'Australia/Melbourne';
console.log(getTimezone(australianTimezone));

Prints to the console:

{
  name: 'Australia/Melbourne',
  country: 'AU',
  utcOffset: 600,
  utcOffsetStr: '+10:00',
  dstOffset: 660,
  dstOffsetStr: '+11:00',
  aliasOf: null
}

From there, you can use the utcOffset or dstOffset depending on if it is daylight savings time.

Using date-fns and date-fns-tz (wrappers for the Javascript date object):

import { differenceInMinutes } from 'date-fns';
import { utcToZonedTime, zonedTimeToUtc } from 'date-fns-tz';

const centralAmericanTimeZone = 'America/Chicago';
const centralEuropeanTimeZone = 'Europe/Paris';

// I am in the central zone
const centralAmericanDateTime = new Date(); 
// Converting my time to UTC
const utcDateTime = zonedTimeToUtc(centralAmericanDateTime, centralAmericanTimeZone);
// Converting UTC to Central European
const centralEuropeanDateTime = utcToZonedTime(utcDateTime, centralEuropeanTimeZone);
// Getting the difference in minutes between UTC and Central European time
const timeDiff = differenceInMinutes(centralEuropeanDateTime, utcDateTime);
// Prints: Central Europe is 420 minutes ahead of UTC
console.log('Central Europe is ', timeDiff, ' minutes ahead of UTC.');

Using countries and timezones npm package:

import {getTimezone} from 'countries-and-timezones';
const australianTimezone = 'Australia/Melbourne';
console.log(getTimezone(australianTimezone));