67.—(1) Where, on any day, there is–
(a)a general interruption or subsequent dislocation in the postal services of the United Kingdom, or
(b)an event or circumstances causing an interruption in the normal operation of the Office,
the registrar may certify the day as being one on which there is an “ interruption” and, where any period of time specified in the Act or these Rules for the giving, making or filing of any notice, application or other document expires on a day so certified the period shall be extended to the first day next following (not being an excluded day) which is not so certified.
(2) Any certificate of the registrar given pursuant to this rule shall be posted in the Office.
(3) If in any particular case the registrar is satisfied that the failure to give, make or file any notice, application or other document within any period of time specified in the Act or these Rules for such giving, making or filing was wholly or mainly attributable to a failure or undue delay in the postal services in the United Kingdom, the registrar may, if she thinks fit, extend the period so that it ends on the day of the receipt by the addressee of the notice, application or other document (or, if the day of such receipt is an excluded day, on the first following day which is not an excluded day), upon such notice to other parties and upon such terms as she may direct.
(4) In this rule “excluded day” means a day which is not a business day of the Office under the registrar’s direction pursuant to section 80, as published in accordance with rule 70 below.