20. The revocation of a document becomes effective on the date specified by the responsible minister or body in the notice of revocation.
Unless otherwise provided by a special provision of the applicable schedule to this Act, the effective date of the revocation, which may precede the date of the notice of revocation, is
(1) the earliest date as of which a condition for the issue of the document is no longer met, if the document is revoked on the ground set out in subparagraph 1 of the third paragraph of section 15;
(2) the date of coming into force of the document, if the document is revoked on the ground set out in subparagraph 2 of the third paragraph of section 15 and the condition of subparagraph a of that subparagraph 2 is met; and
(3) the date determined by the responsible minister or body, in any other case.