from datetime import datetime
from dateutil import tz


def add_tz(dt: datetime, zone: str) -> datetime:
    """add_tz datetime doesnt assign a time zone.  This function shows how to do it.

    Args:
        dt (datetime): original datetime
        zone (str): desired zone 

    Returns:
        datetime: a new datetime with the zone assigned
    """

    return dt.replace(tzinfo=tz.gettz(zone))