About Intellectual Property IP Training IP Outreach IP for… IP and... IP in... Patent & Technology Information Trademark Information Industrial Design Information Geographical Indication Information Plant Variety Information (UPOV) IP Laws, Treaties & Judgements IP Resources IP Reports Patent Protection Trademark Protection Industrial Design Protection Geographical Indication Protection Plant Variety Protection (UPOV) IP Dispute Resolution IP Office Business Solutions Paying for IP Services Negotiation & Decision-Making Development Cooperation Innovation Support Public-Private Partnerships The Organization Working with WIPO Accountability Patents Trademarks Industrial Designs Geographical Indications Copyright Trade Secrets WIPO Academy Workshops & Seminars World IP Day WIPO Magazine Raising Awareness Case Studies & Success Stories IP News WIPO Awards Business Universities Indigenous Peoples Judiciaries Genetic Resources, Traditional Knowledge and Traditional Cultural Expressions Economics Gender Equality Global Health Climate Change Competition Policy Sustainable Development Goals Enforcement Frontier Technologies Mobile Applications Sports Tourism PATENTSCOPE Patent Analytics International Patent Classification ARDI – Research for Innovation ASPI – Specialized Patent Information Global Brand Database Madrid Monitor Article 6ter Express Database Nice Classification Vienna Classification Global Design Database International Designs Bulletin Hague Express Database Locarno Classification Lisbon Express Database Global Brand Database for GIs PLUTO Plant Variety Database GENIE Database WIPO-Administered Treaties WIPO Lex - IP Laws, Treaties & Judgments WIPO Standards IP Statistics WIPO Pearl (Terminology) WIPO Publications Country IP Profiles WIPO Knowledge Center WIPO Technology Trends Global Innovation Index World Intellectual Property Report PCT – The International Patent System ePCT Budapest – The International Microorganism Deposit System Madrid – The International Trademark System eMadrid Article 6ter (armorial bearings, flags, state emblems) Hague – The International Design System eHague Lisbon – The International System of Appellations of Origin and Geographical Indications eLisbon UPOV PRISMA Mediation Arbitration Expert Determination Domain Name Disputes Centralized Access to Search and Examination (CASE) Digital Access Service (DAS) WIPO Pay Current Account at WIPO WIPO Assemblies Standing Committees Calendar of Meetings WIPO Official Documents Development Agenda Technical Assistance IP Training Institutions COVID-19 Support National IP Strategies Policy & Legislative Advice Cooperation Hub Technology and Innovation Support Centers (TISC) Technology Transfer Inventor Assistance Program WIPO GREEN WIPO's Pat-INFORMED Accessible Books Consortium WIPO for Creators WIPO ALERT Member States Observers Director General Activities by Unit External Offices Job Vacancies Procurement Results & Budget Financial Reporting Oversight

Regulations under the PCT

PART D
RULES CONCERNING CHAPTER III OF THE TREATY

Rule 79
Calendar

79.1       Expressing Dates

Applicants, national Offices, receiving Offices, International Searching and Preliminary Examining Authorities, and the International Bureau, shall, for the purposes of the Treaty and the Regulations, express any date in terms of the Christian era and the Gregorian calendar, or, if they use other eras and calendars, they shall also express any date in terms of the Christian era and the Gregorian calendar.