XSLT Date (was: Re: [xsl] keys and idrefs - XSLT2 request?)

[Joerg Pietschmann <joerg dot pietschmann at zkb dot ch>]

"cutlass" <cutlass@secure0.com> wrote:
> and the incomplete list is ;
...
> Dates

This is often mentioned, but what does it mean?
Some random thoughts:
- Having a datetype available for sorting
- Localized formats: Reformat a date into a localized
  representation (without actually changing the calendar).
- Localized parsing: Recognize a localized form of a date as
  such and unambiguously determine which date it is for
  further use in expressions. (i think this is dangerous and
  should *not* be implemented)
- Date comparision
- Date arithmetic: increment a date by N days or months, 
  get the number of days between two dates and so on
- Date functions: get the weekday, day of year, week of
  year, check whether a date is in a leap year and so on
  (ISO definitions)
- Easy validated date construction (day/month/year).
- Non-standard date construction: construct a date from
  year + week-of-year + weekday and so on.
- Validating: Check whether a tentatively constructed date
  would be a valid date, or correct for various failure modes
  (e.g. roll over). Check for valid month, day-in-month and
  so on.
- Localized date functions: use localized definitions for week
  of year and so on instead of ISO definitions.
- Calendars: convert a date into a representation used by a
  non-gregorian calendar.
- Calendar dependent date construction and validating functions.
- Calendar dependent localized date parsing.
- Historical localized calendars: deal with the various
  calendar reforms (geeks only :-)
- Built-in localized month and weekday names and abbreviations
  (gregorian calendar)
- Built-in localized calendar dependent names and abbreviations
  for other calendars.
- Functions related to certain holidays, like easter. (I was
  about to add a smiley, but PHP has it).

Furthermore, should the time of the day be incorporated?
If so, you'll have suddenly to deal with time zones, DST,
leap seconds, accuracy issues and a host of other problems
i don't dare to mention.

Look at the calendar FAQ and shudder. Look at the EMACS
calendar module and shudder even more.

Regards
J.Pietschmann

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