I'm sending this email both to the Time Zone mailing list <tz@elsie.nci.nih.gov> (see <http://www.twinsun.com/tz/tz-link.htm> for more) and to the INMS feedback alias <questions.inms@nrc.ca>, as it seems appropriate for both. INMS, the Institute for National Measurement Standards in Ottawa publishes the following information about standard and daylight saving time zones in Canada: http://www.nrc.ca/inms/time/tze.html (home page) http://www.nrc.ca/inms/images/time/Tz99weB.jpg (standard time, 400 kB) http://www.nrc.ca/inms/images/time/Tz99seB.jpg (daylight saving time, 400 kB) http://www.nrc.ca/inms/faq/time.html#daylight The above web pages report the following information about times since 1988 that disagree with the tz data: * Newfoundland and New Brunswick switch at 00:01 local time, not 02:00. * Manitoba switches from CDT to CST at 03:00 local time, not 02:00. Since this reference seems authoritative, I'm inclined to believe these claims and propose the corresponding changes to the tz data, unless somebody suggests otherwise. This will require creating a new tz Zone entry for New Brunswick; normally this would be America/Saint_John but that's confusing given that there already is an America/St_Johns, so perhaps America/Moncton is a better name. Also, the INMS maps show both "legislated time zone boundaries" and "observed time zones", with the following differences. * British Columbia officially observes PST/PDT, but some parts of east BC observe MST/MDT, and other parts observe MST all year (presumably the America/Dawson_Creek zone of the tz data). * A small area of east Saskatchewan observes CST/CDT, not CST. * A small part of Ontario east of the -90 meridian observes CST/CDT even though it's supposed to observe EST/EDT. Another small part west of -90 observes EST/EDT even though it's supposed to observe CST/CDT. And a third small part west of -90 observes EST all year. * Officially, Quebec east of the -63 meridian is supposed to observe AST all year. But nobody observes this. The western part of east Quebec observes EST/EDT; the eastern part observes AST/ADT. * Most of Labrador observes AST/ADT, even though it's officially supposed to observe NST/NDT. The observed time zones are all covered by existing tz entries, except for the part of Ontario that observes EST all year. Does anybody know more about where that is and how long they've observed EST? The maps don't mention the Baffin time zone rebels reported at length on the tz list. I'll mention the following URL for the benefit of the INMS: http://www.nunatsiaq.com/archives/nunavut991130/nvt91119_17.html