Article 35 Montreal Convention
Article 35 of the Montreal Convention (Convention For the Unification of Certain Rules for International Carriage by Air) is titled Limitation of Actions. It is under Chapter III (Liability of the Carrier and Extent of Compensation for Damage).
1. The right to damages shall be extinguished if an action is not brought within a period of two years, reckoned from the date of arrival at the destination, or from the date on which the aircraft ought to have arrived, or from the date on which the carriage stopped.
2. The method of calculating that period shall be determined by the law of the court seised of the case.
See also: Article 34 Montreal Convention