HCalendar

hCalendar (short for HTML iCalendar) is a microformat standard for displaying a semantic (X)HTML representation of iCalendar-format calendar information about an event, on web pages, using HTML classes and rel attributes.

It allows parsing tools (for example other websites, or browser add-ons like Firefox's Operator extension) to extract the details of the event, and display them using some other website, index or search them, or to load them into a calendar or diary program, for instance. Multiple instances can be displayed as timelines.

Example
Consider this semi-fictional example:

The English Wikipedia was launched on 15 January 2001 with a party from 2-4pm at   Jimmy Wales' house (more information).

The HTML mark-up might be:

hCalendar mark-up may be added using  HTML elements and the classes ,  ,   (start date),   (end date),   and  :

Note the use of the  element to contain the machine readable, ISO8601, date-time format for the start and end times.

Accessibility concerns
Concerns have been expressed that, where it occurs, the use of the  element (using the so-called abbr-design-pattern) in the above manner causes accessibility problems, not least for users of screen readers and aural browsers. The newer h-event microformat therefore uses the HTML5 element  instead:

Geo
The Geo microformat is a part of the hCalendar specification, and is often used to include the coordinates of the event's location within an hCalendar.

Attributes
For a full list of attributes, see the hCalendar cheat-sheet.

Users
Notable organisations and other websites using hCalendar include:


 * Birmingham Town Hall and Symphony Hall
 * Facebook
 * Google (in Google maps and in Search Engine Results Pages )
 * The Opera web browser website
 * The Radio Times
 * The University of Bath
 * The University of Washington
 * Upcoming.org
 * Wikipedia
 * Yahoo!, on Yahoo! Local