HCalendar

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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.

1 Example
2 Exclusive end-dates
3 Accessibility concerns
4 Geo
5 Attributes
6 Users
7 References
8 External links

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="/redirect?url=aHR0cDovL2VuLndpa2lwZWRpYS5vcmcvd2lraS9IaXN0b3J5X29mX1dpa2lwZWRpYQ%3D%3D">more information</a>)
</p>

We can add hCalendar mark-up 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">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="/redirect?url=aHR0cDovL2VuLndpa2lwZWRpYS5vcmcvd2lraS9IaXN0b3J5X29mX1dpa2lwZWRpYQ%3D%3D">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.

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:


 <abbr class="dtend" title="2001-02-01">31 January 2001</abbr>

Accessibility concerns

Concerns have been expressed ^[1] 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 ^[2]. 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.