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[1] 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 expressed[2] 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.[3] 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[4]
- Facebook[5]
- Google (in Google maps[6] and in Search Engine Results Pages [7][8])
- The Opera web browser website[9]
- The Radio Times[10]
- The University of Bath[10]
- The University of Washington[10]
- Upcoming.org[10]
- Wikipedia[11]
- Yahoo!, on Yahoo! Local[10]
References
- ^ Microformats.org: Browser Support for Microformats
- ^ Web Standards Project, hAccessibility: Abbreviations in Microformats
- ^ Microformats Wiki: Assistive Technology
- ^ Microformats - Birmingham City Council
- ^ Protalinski, Emil (2011-02-18). "Facebook adds hCalendar and hCard microformats to Events". ZDNet. Retrieved 24 March 2011.
- ^ Official Google Maps API Blog: Microformats in Google Maps
- ^ Microformats.org: Google adds support for hCalendar and hRecipe Rich Snippets
- ^ Google Webmaster Tools: Rich snippets - Events
- ^ David Storey - Microformats on Opera sites
- ^ a b c d e hCalendar Examples in the wild · Microformats Wiki
- ^