A user account is required in order to edit this wiki, but we've had to disable public user registrations due to spam.

To request an account, ask an autoconfirmed user on Chat (such as one of these permanent autoconfirmed members).

Time element: Difference between revisions

From WHATWG Wiki
Jump to navigation Jump to search
(tei)
Line 53: Line 53:
<div class="discussion">
<div class="discussion">
Opinions / discussion:
Opinions / discussion:
* +1 [[User:Pigsonthewing|Andy Mabbett]] (Per use cases in VCARDDAV & EDTF - see external links)
* +1 [[User:Pigsonthewing|Andy Mabbett]] (Per use cases in VCARDDAV, EDTF & TEI - see external links)
* ...
* ...
</div>
</div>
Line 62: Line 62:
<div class="discussion">
<div class="discussion">
Opinions / discussion:
Opinions / discussion:
* +1 [[User:Pigsonthewing|Andy Mabbett]] (Per use cases in "Extended Date Time Format" proposals - see external links)
* +1 [[User:Pigsonthewing|Andy Mabbett]] (Per use cases in "Extended Date Time Format" proposals & TEI - see external links)
* ...
* ...
</div>
</div>
Line 86: Line 86:
*** [http://www.ietf.org/mail-archive/web/vcarddav/current/msg01307.html VCARDDAV discussion of CALSCALE]
*** [http://www.ietf.org/mail-archive/web/vcarddav/current/msg01307.html VCARDDAV discussion of CALSCALE]
* [http://www.tei-c.org/Guidelines/P4/html/ref-DATE.html TEI dates], widely used   
* [http://www.tei-c.org/Guidelines/P4/html/ref-DATE.html TEI dates], widely used   
by archives and libraries to mark up texts, including non-Gregorian ISO8601 dates
by archives and libraries to mark up texts, including non-Gregorian ISO8601 & uncertain/ approximate dates
* [http://en.wikipedia.org/wiki/ISO_8601 ISO 8601 (Wikipedia article)]
* [http://en.wikipedia.org/wiki/ISO_8601 ISO 8601 (Wikipedia article)]

Revision as of 21:13, 14 July 2010

Research, data, use cases, issues, and enhancements related to the HTML5 time element.

year only

The time element should accept just a year.

ISO8601 syntax
YYYY
use case research
http://microformats.org/wiki/birthday-examples#year_only

Opinions / discusion:

year month only

The time element should accept just a year and a month.

ISO8601 syntax
YYYY-MM

Opinions / discusion:

month day only

The time element should accept just a month and a day.

ISO8601 syntax
--MM-DD
use case research
http://microformats.org/wiki/birthday-examples#month_and_day_only

Opinions / discusion:

Calendar

The time element should accept a calendar scale (CALSCALE; default is GREGORIAN) per the emergent vCard 4 specification, to allow for the the mark-up of non-Gregorian (e.g. Julian) dates, using some as-yet-to-be-formulated CALSCALE type.

Opinions / discussion:

  • +1 Andy Mabbett (Per use cases in VCARDDAV, EDTF & TEI - see external links)
  • ...

Fuzzy dates

The time element should accept fuzzy (uncertain, approximate) dates and eras.

Opinions / discussion:

  • +1 Andy Mabbett (Per use cases in "Extended Date Time Format" proposals & TEI - see external links)
  • ...

Specification ambiguities

The specification requires that time be expressed as UTC (or another time zone with a specified offset from UTC). However, the representation of leap seconds is not specified. Further, the algorithms to convert between string and number are flawed, because the number is described as "number of milliseconds elapsed from midnight UTC on the morning of 1970-01-01" but the actual number of milliseconds includes all kinds of strange decisecond offsets during the period 1961-01-01 to 1972-01-01. Also, UTC did not exist before about 1960.

Unix timekeeping has a long history of terrible definitions, and Unix notions of time should be totally rejected and expunged.

Choose different default date

The statement that valueAsDate IDL attribute should return the value 1970-01-01 plus the appropriate time when the time element contains no date creates a problem that there are likely to be time elements that explicitly contain that date.

A better choice would be a value that is highly unlikely to be encountered, and would be implausible as an actual date in most applications, perhaps 9999-12-31.

External links

by archives and libraries to mark up texts, including non-Gregorian ISO8601 & uncertain/ approximate dates