setTimezone = timezone => {
    if (currTimezone === timezone) {
      return;
    }
    currTimezone = timezone;
  }
Sets the IANA timezone ID.
<b>For example:</b> "America/New_York", "Europe/London", "Australia/Sydney", "Asia/Bishkek", etc.
>
@param {string} timezone
@private
@returns { Promise<void> }