function getTimeZoneBrowser() {
  let date = new Date();
  return ("(GMT" + getTimeZoneOffsetFromGMT(date) + ") " + getTimeZonePortionOfCountryCovered(date) + getTimeZoneDatabaseName());
}

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

function getTimeZonePortionOfCountryCovered(date) {
  return date.toString().replace(/(.*\((.*)\).*)/, '$2');
}

function getTimeZoneDatabaseName() {
  var tzdbn = Intl.DateTimeFormat().resolvedOptions().timeZone;
  if (typeof tzdbn != "undefined")
    return " (" + tzdbn + ")";
  else
    return "";
}