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Supported specifications

This page outlines iCalendar specifications supported by iCal4j.


iCalendar is a collection of specifications that define a set of rules and data formats to be implemented by a Calendar User Agent (CUA). Implementation of these specifications should provide a CUA with the ability to interact with other CUAs via calendaring and scheduling workflows.


  • RFC5545 - Internet Calendaring and Scheduling Core Object Specification (iCalendar)
  • RFC5546 - iCalendar Transport-Independent Interoperability Protocol (iTIP)
  • RFC6047 - iCalendar Message-Based Interoperability Protocol (iMIP)
  • RFC6868 - Parameter Value Encoding in iCalendar and vCard
  • RFC7953 - Calendar Availability
  • RFC7986 - New Properties for iCalendar
  • RFC7529 - Non-Gregorian Recurrence Rules in iCalendar
  • RFC9073 - Event Publishing Extensions to iCalendar
  • RFC9074 - "VALARM" Extensions for iCalendar