The notice period defined in Rule 115(1), i.e. at least two months, is valid also in the case of a change of date unless the parties have agreed on a shorter period (see also E‑III, 6(iii), and E‑III, 8.11.1).
Source: http://www.epo.org/law-practice/legal-texts/html/guidelines/e/e_iii_7_1_3.htm
Date retrieved: 17 May 2021