[uf-discuss] Events with no duration; and end of daylight saving time

Brian Suda brian.suda at gmail.com
Sat Aug 26 16:33:14 PDT 2006

On 8/26/06, Andy Mabbett <andy at pigsonthewing.org.uk> wrote:
> What's the correct way to mark up an hCal for an event which has no
> duration?

The only two properties that are required (besides the class="vevent")

If there is no end-date or duration this can simply be omitted.

> And what's the correct way in which to mark up the event when, at the
> end of daylight saving time, clocks go back from 3am to 2am - as a
> single event at 3am?

I don't think this is an issue for hCalendar. If you have an event
that passes between the start/stop of daylight savings you have
several options to mark-up the event. (NOTE: this only effects events
with specifc start/stop TIMES)

Lets assume you live in the USA Central Standard Time zone, Normally 6
hours ahead of UTC, only 5 hours ahead during day light saving.

Option 1:
<abbr class="dtstart" title="2006-01-01T12:00:00-0600">Noon, January
1st 2006</abbr>
<abbr class="dtend" title="2006-06-01T12:00:00-0500">Noon, January 1st

This explicitly using a timezone offset, because of this you manually
would have to add the appropriate +/- for the hours off of UTC. I'm
not sure how importing applications would handle this? they might
apply those timezone offsets in relation to the CURRENT timezone
offset - not sure? Option 2 is a better choice.

Assuming we are still in Central Standard Time
Option 2:
<abbr class="dtstart" title="2006-01-01T18:00:00Z">Noon, January 1st 2006</abbr>
<abbr class="dtend" title="2006-01-01T18:00:00Z">Noon, June 1st 2006</abbr>

Your local application will compute the time of the event based on the
time in UTC (18:00:00) and adjust it to your current Timezone (which
SHOULD) also correct because your system clock will be adjusted based
on Day Light Savings

I hope that helps answer you question?

brian suda

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