hCalendar (short forHTML iCalendar) is amicroformat standard for displaying a semantic(X)HTML representation ofiCalendar-formatcalendar information about an event, onweb pages, using HTML classes andrel attributes.
It allows parsing tools (for example other websites, or browser add-ons[1] likeFirefox'sOperator 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.
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 (<ahref="http://en.wikipedia.org/wiki/History_of_Wikipedia">more information</a>)</p>
hCalendar mark-up may be added usingspanHTML elements and theclassesvevent,summary,dtstart (start date),dtend (end date),location andurl:
<pclass="vevent"> The<spanclass="summary">English Wikipedia was launched</span> on 15 January 2001 with a party from<abbrclass="dtstart"title="2001-01-15T14:00:00+06:00">2pm</abbr>-<abbrclass="dtend"title="2001-01-15T16:00:00+06:00">4pm</abbr> at<spanclass="location">Jimmy Wales' house</span> (<aclass="url"href="http://en.wikipedia.org/wiki/History_of_Wikipedia">more information</a>)</p>
Note the use of theabbr element to contain the machine readable,ISO8601, date-time format for the start and end times.
Concerns have been expressed[2] that, where it occurs, the use of theabbr element (using the so-calledabbr-design-pattern) in the above manner causes accessibility problems, not least for users of screen readers and aural browsers.[3] The newerh-event microformat therefore uses theHTML5 elementtime instead:
<timeclass="dt-start"datetime="2013-06-30 12:00">30<sup>th</sup>June2013,12:00</time>
TheGeo 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 thehCalendar cheat-sheet.
Notable organisations and other websites using hCalendar include: