'Return the value of a query string parameter as a date.
Args:
name (str): Parameter name, case-sensitive (e.g., \'ids\').
Keyword Args:
format_string (str): String used to parse the param value
into a date. Any format recognized by strptime() is
supported (default ``"%Y-%m-%d"``).
required (bool): Set to ``True`` to raise
``HTTPBadRequest`` instead of returning ``None`` when the
parameter is not found (default ``False``).
store (dict): A ``dict``-like object in which to place
the value of the param, but only if the param is found (default
``None``).
Returns:
datetime.date: The value of the param if it is found and can be
converted to a ``date`` according to the supplied format
string. If the param is not found, returns ``None`` unless
required is ``True``.
Raises:
HTTPBadRequest: A required param is missing from the request.
HTTPInvalidParam: A transform function raised an instance of
``ValueError``.'

def get_param_as_date(self, name, format_string='%Y-%m-%d', required=False, store=None):

    date_time = self.get_param_as_datetime(name, format_string, required)
    if date_time:
        date = date_time.date()
    else:
        return None
    if (store is not None):
        store[name] = date
    return date
