How is the relevant date determined for prior art in international patent examinations?

The relevant date for considering prior art in international patent examinations is determined according to MPEP 1843.01, which references PCT Rule 64.1(b):

• Generally, it’s the international filing date of the application under examination
• If the application claims priority of an earlier application and has an international filing date within the priority period, it’s the filing date of the earlier application
• Special provisions apply for applications filed shortly after the priority period expiration

The MPEP states: “The relevant date for the purpose of considering prior art for the purposes of establishment of the written opinion of the International Searching Authority is defined in PCT Rule 64.1(b) as the international filing date or, where the international application contains a claim for priority, the date provided in PCT Rule 64.1(b)(ii) – (iii).”

To learn more:

• relevant date
• prior art
• international patent examination
• PCT Rule 64.1
• priority date