Try out our new RRULE tool for creating RRULE compatible strings.

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119].

This memo makes use of both a descriptive prose and a more formal notation for defining the calendaring and scheduling format.

The notation used in this memo is the ABNF notation of [RFC5234]. Readers intending on implementing the format defined in this memo should be familiar with this notation in order to properly interpret the specifications of this memo.

All numeric values used in this memo are given in decimal notation.

All names of properties, property parameters, enumerated property values, and property parameter values are case-insensitive. However, all other property values are case-sensitive, unless otherwise stated.


All indented editorial notes, such as this one, are intended to provide the reader with additional information. The information is not essential to the building of an implementation conformant with this memo. The information is provided to highlight a particular feature or characteristic of the memo.

The format for the iCalendar object is based on the syntax of the text/directory media type [RFC2425]. While the iCalendar object is not a profile of the text/directory media type [RFC2425], it does reuse a number of the elements from the [RFC2425] specification.

This document was automatically converted to XHTML using an RFC to HTML converter with the original text document at the Internet Engineering Task Force web site at .  The original text document should be referred to if there are any errors or discrepancies found in this document.

Need to test your iCalendar feeds?

The iCalendar Validator provides developers and testers a method to validate their iCalendar feeds, which can take data from either a URL, file or text snippet and compare it against the RFC 5545 specification.  We believe we have one of the best iCalendar validation tools available on the internet. More information about the validator can be found here.