If the Secretary revokes a conformity assessment certificate, or varies a conformity assessment certificate under subsection 41EU(2), the revocation or variation has effect:
(a) if the revocation is under section 41ER or 41ES, or the variation relates to a ground of revocation in section 41ER or 41ES--on the day on which the notice of revocation or variation is given to the person in relation to whom the certificate was issued; or
(b) in any other case--on such later day as is specified in the notice.