@property<EOL><INDENT>def is_expired(self):<DEDENT>
expiration_time = self.created_at + datetime.timedelta(days=<NUM_LIT:1>)<EOL>return timezone.now() > expiration_time<EOL>
Determine if the confirmation has expired.

Returns:
    bool:
        ``True`` if the confirmation has expired and ``False``
        otherwise.