- From: Eric van der Vlist <vdv@dyomedea.com>
- Date: Sun, 28 Oct 2001 17:33:36 +0100
- To: xmlschema-dev@w3.org
Knowing that: "3.2.13 gDay [Definition:] gDay is a gregorian day that recurs, specifically a day of the month such as the 5th of the month. Arbitrary recurring days are not supported by this datatype. The ·value space· of gDay is the space of a set of calendar dates as defined in § 3 of [ISO 8601]. Specifically, it is a set of one-day long, monthly periodic instances." I assume that the algorithm defined in "E Adding durations to dateTimes" is used to iterate over the different dates, including the rule about "pinning": "Essentially, this calculation is equivalent to separating D into <year,month> and <day,hour,minute,second> fields. The <year,month> is added to S. If the day is out of range, it is pinned to be within range. Thus April 31 turns into April 30. Then the <day,hour,minute,second> is added. This latter addition can cause the year and month to change." In other words, "--31" would iterate over Jan 31st, Feb 28th (or 29th depending on the year), Mar 31th, Apr 30th, ... While this seems logical, I think that this should be better described in the recommendation. The side effect is that if you look at the number of days between two iterations for "--28", --29, 30 and "--31" you have (for a non leap year): Jan Feb Mar Apr May Jun --28 31 28 31 30 31 --29 30 29 31 30 31 --30 29 30 31 30 31 --31 28 31 30 31 30 IMO, this is not fully conform with the sentence "Specifically, it is a set of one-day long, monthly periodic instances" since adding a month to CCYY-02-28 should give CCYY-03-28 and that with my interpretation, the result is kind of context dependent. The same effect happens for "-02-29"... Thanks Eric -- Rendez-vous ą Paris pour le Forum XML. http://www.technoforum.fr/Pages/forumXML01/index.html ------------------------------------------------------------------------ Eric van der Vlist http://xmlfr.org http://dyomedea.com http://xsltunit.org http://4xt.org http://examplotron.org ------------------------------------------------------------------------
Received on Sunday, 28 October 2001 12:48:01 UTC