IPR HelpDesk Summarizes European Grace Period Requirements
Disclosure of an invention is not taken into account if it occurred less than six months before the filing of a patent application and if:
(1) a third person has disclosed the invention in an abusive way that obviously harms the applicants' interests;
(2) the applicant has displayed the invention at an official international exhibition falling within the terms of the Convention on international exhibitions.
. . . [however,] the Spanish patent law offers a grace period for tests carried out by the applicant or by his legal predecessor provided that they do not imply using the invention or offering it for sale, and that they were carried out during the six months preceding the filing of the application. Under Portuguese patent law, the novelty of an invention shall not be eliminated by communications made before scientific societies or professional technical associations or for the purpose of Portuguese or international competitions or exhibitions if the patent application is filed in Portugal within 12 months. Furthermore, the grace period for abusive disclosures does not have any time limit.
Applications for community design registration, on the other hand, can be filed up to a year after the first disclosure of a design without the designer's own disclosures counting against the registration. Six month grace periods for utility model applications are available in some countries.
For more on countries outside of Europe, see "Grace Period and Invention Law in Europe and Selected States."