CODE EXAMPLE FOR JAVASCRIPT

get offset from timezone javascript

// Following function can be used to return the UTC offset given a timezone:

const getTimezoneOffset = (timeZone, date = new Date()) => {
  const tz = date.toLocaleString("en", {timeZone, timeStyle: "long"}).split(" ").slice(-1)[0];
  const dateString = date.toString();
  const offset = Date.parse(`${dateString} UTC`) - Date.parse(`${dateString} ${tz}`);
  
  // return UTC offset in millis
  return offset;
}


//It can be used like:

const offset = getTimezoneOffset("Europe/London");
console.log(offset);
// expected output => 3600000