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.

It allows parsing tools (for example other websites, or 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:

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

We can add hCalendar mark-up using span HTML elements and the classes vevent, summary, dtstart (start date), dtend (end date), location and url:

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

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

Exclusive end-dates

For whole-day dates, where no time is specified, the end-date must be recorded as "exclusive" (i.e. the day "after" the event ends). For example:

31 January 2001

Accessibility concerns

Concerns have been expressed [ [http://www.webstandards.org/2007/04/27/haccessibility/ Web Standards Project, hAccessibility: Abbreviations in Microformats] ] that the use of the abbr element (using the so-called [http://microformats.org/wiki/abbr-design-pattern abbr-design-pattern] ) in the above manner causes accessibility problems, not least for users of screen readers and aural browsers. Work is underway to find an alternative method of presenting ISO8601 date-time information [ [http://microformats.org/wiki/assistive-technology Microformats Wiki: Assistive Technology] ] . This is particularly problematic for exclusive end-dates (see above example).

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 [http://microformats.org/wiki/hcalendar-cheatsheet hCalendar cheat-sheet] .

Users

Notable organisations and other websites using hCalendar include:
*Birmingham Town Hall and Symphony Hall
*Google (in Google maps)
*The Opera web browser website [http://my.opera.com/dstorey/blog/microformats-on-opera-sites]
*The Radio Times
*The University of Bath
*The University of Washington
*Upcoming.org
*Wikipedia
*Yahoo!, on Yahoo! Local

References

External links

* [http://microformats.org/wiki/hcalendar hCalendar at the Microformats Wiki]