JSFiddle - React, Tailwind, and code Playground

JavaScript

function getTimeZone() {
    var offset = new Date().getTimezoneOffset(),
        o = Math.abs(offset);
    return (offset < 0 ? "+" : "-") + ("00" + Math.floor(o / 60)).slice(-2) + ":" + ("00" + (o % 60)).slice(-2);
}

console.log(getTimeZone());