13152 2011-07-05 19:59:50 +0000 How can DST be derived from time zone offset -04:00? 2011-08-04 05:34:59 +0000 1 1 1 Unclassified HTML WG LC1 HTML5 spec unspecified Other other RESOLVED NEEDSINFO http://www.whatwg.org/specs/web-apps/current-work/#global-dates-and-times P3 minor --- 1 contributor ian ayg lbloom mike philipj public-html-admin public-html-wg-issue-tracking public-html-bugzilla oldest_to_newest 50692 0 contributor 2011-07-05 19:59:50 +0000 Specification: http://www.whatwg.org/specs/web-apps/current-work/multipage/common-microsyntaxes.html Multipage: http://www.whatwg.org/C#global-dates-and-times Complete: http://www.whatwg.org/c#global-dates-and-times Comment: How can DST be derive d from time zone offset -04:00? Posted from: 93.216.203.46 User agent: Mozilla/5.0 (Windows NT 6.1; rv:5.0) Gecko/20100101 Firefox/5.0 50710 1 philipj 2011-07-06 08:26:12 +0000 It can't, DST is part of the offset. To know if DST applies, you have to know which country the timestamp is from, as DST varies depending on what lawmakers pull out of their hats. 50746 2 ayg 2011-07-06 20:06:46 +0000 This does not appear to contain any feedback on the specification. Marking INVALID. For information about daylight saving time, the Wikipedia article is probably a good place to look: http://en.wikipedia.org/wiki/Daylight_saving_time 50747 3 lbloom 2011-07-06 20:14:01 +0000 To cite the current spec: "1979-10-14T12:00:00.001-04:00 One millisecond after noon on October 14th 1979, in the time zone in use on the east coast of the USA during daylight saving time." This is confusing, since the time zone cannot be derived from the offset. Offset to time zone is a 1:n correspondence. 50758 4 ayg 2011-07-06 21:39:44 +0000 EDITOR'S RESPONSE: This is an Editor's Response to your comment. If you are satisfied with this response, please change the state of this bug to CLOSED. If you have additional information and would like the Editor to reconsider, please reopen this bug. If you would like to escalate the issue to the full HTML Working Group, please add the TrackerRequest keyword to this bug, and suggest title and text for the Tracker Issue; or you may create a Tracker Issue yourself, if you are able to do so. For more details, see this document: http://dev.w3.org/html5/decision-policy/decision-policy.html Status: Additional Information Needed Change Description: no spec change Rationale: What exactly is incorrect with the spec text you cite? UTC-04:00 is in fact the time zone in use on the east coast of the USA during daylight saving time. It is also the time zone in use in a number of other places, such as parts of Latin America and the Caribbean, but that doesn't make the example incorrect. 50796 5 lbloom 2011-07-07 21:13:09 +0000 (In reply to comment #4) > Rationale: What exactly is incorrect with the spec text you cite? UTC-04:00 is > in fact the time zone in use on the east coast of the USA during daylight > saving time. It is also the time zone in use in a number of other places, such > as parts of Latin America and the Caribbean, but that doesn't make the example > incorrect. OK. My first reading of the example was that the time zone (... in use on the east coast of the USA during daylight saving time) would be implied by the given date-time literal, what is certainly not correct. But as far as I can see, the only time zone that is relevant for this spec is UTC, what perfectly corresponds with the lack of calendaring support in ECMAScript. So the example may probably not confuse readers too much. Sorry for the noise. 53973 6 mike 2011-08-04 05:34:59 +0000 mass-move component to LC1