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