(a) Any Contracting State allowing a time limit expiring later than the time limits provided for in Article 22(1) or (2) shall notify the International Bureau of the time limits so fixed.
(b) Any notification received by the International Bureau under paragraph (a) shall be promptly published by the International Bureau in the Gazette.
(c) Notifications concerning the shortening of the previously fixed time limit shall be effective in relation to international applications filed after the expiration of three months computed from the date on which the notification was published by the International Bureau.
(d) Notifications concerning the lengthening of the previously fixed time limit shall become effective upon publication by the International Bureau in the Gazette in respect of international applications pending at the time or filed after the date of such publication, or, if the Contracting State effecting the notification fixes some later date, as from the latter date.
Source: http://www.wipo.int/pct/en/texts/articles/r50.htm
Date retrieved: 17 May 2021