def display_datetime(datetime_str, time_zone=None, verbose=True):
    """Returns a formatted datetime with TZ (if provided) or 'Error (Missing)"""
    """      
    >>> print(datetime.datetime.utcnow().strftime("%Y/%m/%d %a %I:%M %p"))
    2019/05/19 Sun 01:10 AM
    """
    if datetime_str:  # and type(datetime_str) == datetime.datetime.now():
        if verbose:
            return f'{datetime_str.strftime("%Y/%m/%d %a %I:%M %p")}{f" ({time_zone})" if time_zone else ""}'
        else:
            return f'{datetime_str.strftime("%a %I:%M %p")}{f" ({time_zone})" if time_zone else ""}'
    else:
        return 'Error (Missing)'