In J 14/86 (OJ 1988, 85) the Legal Board held that the fact that R. 83(2) EPC 1973 (R. 131(2) EPC) fixed the point in time from which all the time limits ran and defined this point as the day following that on which the event giving rise to the time limit occurred, could not be interpreted as requiring the addition of a day to time limits expressed in years, months and weeks, hence the grant of an additional day for reasons of equity. The expiry date of time limits expressed in years, months or weeks was derived from R. 83(3) to (5) EPC 1973. These paragraphs, in conjunction with paragraph 2 of the same rule, established unequivocally that the time limits were fixed in full years, months and weeks, without any possibility of their being reduced or extended (see also J 9/82, OJ 1983, 57).

In J 13/88 the Legal Board demonstrated how to calculate the 12-month priority period referred to in Art. 87 EPC. The event representing the point in time from which a time limit started to run was the filing date of the application in respect of which priority was claimed, which was 5 May 1986. The period expired in the relevant subsequent month on the day which had the same number as the day on which the said event occurred, which was 5 May 1987 (R. 83(2) EPC 1973 in combination with R. 83(4) EPC 1973).

T 2056/08 concerns the calculation of the period for filing an appeal when combined with a ten-day period for postal delivery. The board noted that the two-month period stipulated in Art. 108 EPC started from the day of the presumed or actual notification. If any rule of thumb could be suggested to calculate the appeal period, it should be "ten days plus two months" rather than "two months plus ten days."

R 18/10 concerned the calculation of the two-month time limit under Art. 112a(4) EPC. The relevant decision had been posted on 31 August 2010 and the actual notification occurred on 6 September 2010. According to R. 131(2) EPC, where a procedural step is a notification, the relevant event shall be the receipt of the document notified, unless otherwise provided. According to R. 126(2) EPC, in cases where notification is effected by registered letter such a letter is deemed to be delivered to the addressee on the tenth day following its posting. Therefore, regardless of the fact that actual notification occurred on 6 September 2010 the time limit ended pursuant to R. 126(2) EPC on 10 November 2010.

For events which trigger the start of a time limit in connection with re-establishment of rights, see below chapter III.E.4.1.1 "Two-month time limit from the removal of the cause of non-compliance"; for "notification" as an event which triggers the start of a time limit, see chapter III.S.; for the relevant event for calculating the time limit under Art. 78(2) EPC 1973 (R. 38 EPC), see J 13/04.