How do Japanese patent application publications show dates?

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Source: FAQ (MPEP-Based) BlueIron Update: 2024-09-27 2 Rules 5 Related FAQs This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice. Japanese patent application publications use a unique system for indicating dates. According to MPEP 901.05(a) : “Japanese patent application publications show the date in Arabic numerals by indicating in order the year of the reign of the Emperor, the month, and the day.” This means that Japanese patent dates are typically formatted as YY.MM.DD, where YY represents the year of the Emperor’s reign, not the Western calendar year. Related Rules from the Manual of Patent Examining Procedure 2 rules Collapse Requirement for Examiner's Action Under 1.104(a)(1) MPEP 901 Declassified Patent Application Required MPEP 130 Other Related FAQs 5 FAQs Collapse How do you convert Japanese patent dates to Western calendar years? How are dates formatted in foreign patent publications? Why is understanding foreign patent date formats important for patent research? What do Roman numerals represent in foreign patent publication dates? Can an abandoned application be used as prior art?