Timezone independent events/events that lasts the whole day?

[annando]

"startTime" and "endTime" always seem to contain a timezone. Friendica does also support some timezone independent events. This can be used for events like the "earth hour": https://en.wikipedia.org/wiki/Earth_Hour This event is always from 20:30 to 21:30 local time. So when I transmit this to my followers around the earth, it must not be adapted to their timezone, but has to be kept at "20:30" of their local time. How could that be done?

And: How could I transmit an event that lasts the whole days?

[nightpool]

looks like https://www.w3.org/TR/activitystreams-core/#dates is pretty clear that it doesn't support this :( It requires all times to have either an offset or Z utc specifier.

[annando]

I know. That's why I'm asking how this could be done. :-)

Edit: What would you suggest for events that last a whole day?

[NDC431]

.

เมื่อ 6 ต.ค. 2018 23:43 "Michael Vogel" [email protected] เขียนว่า

I know. That's why I'm asking how this could be done. :-)

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[annando]

Of course one could always transmit some extra flag and the UTC time. This would then be a sign for these kinds of events.

[swift2plunder]

I think it's probably best to use an existing open data format, like CalDAV, for the content of Events and leave the date format for dating the Objects, themselves.

[lisad]

A note about how iCalendar supports this (RFC 5545, 3.2.19. Time Zone Identifier):

      The parameter [TZID] MUST be specified on properties with a DATE-TIME
      value if the DATE-TIME is not either a UTC or a "floating" time.

Thus, a floating-time event is inferred by the lack of a TZID. as commenters have noted above, that's not an approach we can use with AcitivtyStreams now.

[evanp]

So, for the first question: I don't think we have support for that type of event. The best workaround I can think of right now is to make ~24 events for the different time zones (and I realize that's a very complex process!). If we wanted to support other types of date format, we would need to make a normative change to AS2, since it has a fixed format for dates, including startTime and endTime.

[evanp]

I think for events that last entire days, there's no limit on the starttime/endtime. So you could do startTime equal to 2024-12-25T00:00:00Z and endTime equal to 2024-12-26T00:00:00Z to indicate the full day. However, we don't have a way to say "25 December 2024 in your timezone, all day".

[evanp]

I'm going to add these two points as clarifying notes in the ActivityPub Primer. I think there is some room for extension properties that could be used instead for "in your own timezone" events.

[TallTed]

It might be worthwhile to (also) complain upstream, to ISO and IETF and other specifiers of datetime format specifications upon which so many other systems and specifications rely, that their formats have no way to handle such "local" timezone values. It also seems to me that those format specifications would be improved by the addition of an "anywhere on earth" (or similar) TZ, being particularly but not only useful for sweepstakes, giveaways, and similar things.

[github-actions[bot]]

This issue has been labelled as potentially needing a FEP, and contributors are welcome to submit a FEP on the topic. Note that issues may be closed without the FEP being created; that does not mean that the FEP is no longer needed.

[evanp]

I think the easiest way to do this is with a FEP that specifies a time-zone-independent start time property, like startTimeLocal and endTimeLocal. I'm also going to add the primer page on times.

[evanp]

We already have a primer page on this, so I am going to close the issue. The needs-fep flag will continue to indicate that a vocabulary extension may be warranted.

https://www.w3.org/wiki/Activity_Streams/Primer/Timestamps