Template:Lowercase 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.
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>
<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">2</abbr>- <abbr class="dtend" title="2001-01-15T16:00:00+06:00">4</abbr>pm 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.
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:
<abbr class="dtend" title="2001-02-01">31 January 2001</abbr>
Concerns have been expressed  that 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. Work is underway to find an alternative method of presenting ISO8601 date-time information . This is particularly problematic for exclusive end-dates (see above example).
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.
For a full list of attributes, see the hCalendar cheat-sheet.
Notable organisations and other websites using hCalendar include:
- Birmingham Town Hall and Symphony Hall
- Google (in Google maps)
- The Opera web browser website
- The Radio Times
- The University of Bath
- The University of Washington
- Yahoo!, on Yahoo! Local
<ref>tags exist, but no
<references/>tag was found