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-onsMicroformats.org: Browser Support for Microformats 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:
<p> The English Wikipedia was launched on 15 January 2001 with a party from 2-4pm at Jimmy Wales' house (<a href="http://en.wikipedia.org/wiki/History_of_Wikipedia">more information</a>) </p>
hCalendar mark-up may be added using span HTML elements and the classes vevent, summary, dtstart (start date), dtend (end date), location and url:
<p class="vevent"> The <span class="summary">English Wikipedia was launched</span> on 15 January 2001 with a party from <abbr class="dtstart" title="2001-01-15T14:00:00+06:00">2pm</abbr>- <abbr class="dtend" title="2001-01-15T16:00:00+06:00">4pm</abbr> at <span class="location">Jimmy Wales' house</span> (<a class="url" href="http://en.wikipedia.org/wiki/History_of_Wikipedia">more information</a>) </p>
Note the use of the abbr element to contain the machine readable, ISO8601, date-time format for the start and end times.
Accessibility concerns
Concerns have been expressedWeb Standards Project, hAccessibility: Abbreviations in Microformats that, where it occurs, the use of the abbr 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.Microformats Wiki: Assistive Technology The newer h-event microformat therefore uses the HTML5 element time instead: <time class="dt-start" datetime="2013-06-30 12:00">30<sup>th</sup> June 2013, 12:00</time>
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 mapsOfficial Google Maps API Blog: Microformats in Google Maps and in Search Engine Results Pages Microformats.org: Google adds support for hCalendar and hRecipe Rich SnippetsGoogle Webmaster Tools: Rich snippets - Events) The Opera web browser websiteDavid Storey – Microformats on Opera sites The Radio Times The University of BathhCalendar Examples in the wild · Microformats Wiki The University of Washington Upcoming.org WikipediaWikipedia:Microformats Yahoo!, on Yahoo! Local
References
External links hCalendar at the Microformats Wiki