1.5 Effect of change in priority date 

Certain time limits run from the date of priority, or if there are several priorities, from the earliest date of priority. Where this date no longer applies (e.g. the right of priority is lost in accordance with Art. 90(5)), these time limits are to be calculated as from the amended date of priority. This does not restore any rights lost because a time limit had already expired before the loss of priority date. For example, if a request for restoration of a priority right is filed on entry into the European phase on expiry of the 31-month time limit under Rule 159(1) but the request is not granted and the right of priority is lost as a result, the 31-month time limit will not be deferred. Part A of the Guidelines deals with the procedure to be followed (see A‑III, 6.9 to A-III, 6.11).