"(3) If a complainant chooses to present a complaint by sending it by post, presentation will be assumed to have been affected, unless the contrary is proved, at the time when the letter would have been delivered in the ordinary course of post: see by analogy,section 7 of the Interpretation Act 1978 . (4) If the letter is sent by first class post, it is now legitimate to adapt the approach contained inCPR r6.7 and conclude that in the ordinary course of post it will be delivered on the second day after it was posted (excluding Sundays, bank holidays, Christmas Day and Good Friday, being days when post is not normally delivered). (5) If the letter does not arrive at the time when it would be expected to arrive in the ordinary course of post, but is unexpectedly delayed, a tribunal may conclude that it was not reasonably practicable for the complaint to be presented within the prescribed period. (6) If a form is date-stamped on a Monday by a tribunal office so as to be outside at three-month period which ends on the Saturday or Sunday, it will be open to a tribunal to find as a fact that it was posted by first class post not later than the Thursday and arrived on the Saturday, alternatively to extend time as a matter of discretion if satisfied that the letter was posted by first class post not later than the Thursday."