[tz] Welcome to the "tz" mailing list

Sundar Sarma gkssarma59 at gmail.com
Wed May 20 16:55:12 UTC 2020


Is Yukon part of Canada/Mountain?

Regards,
Sundar

On Wed, May 20, 2020 at 8:47 PM Brian Inglis <
Brian.Inglis at systematicsw.ab.ca> wrote:

> On 2020-05-20 05:32, Sundar Sarma wrote:
> > According to the latest 2020a tz update: Canada's Yukon, represented by
> > America/Whitehorse and
> >     America/Dawson, advanced to -07 year-round, beginning with its
> >     spring-forward transition on 2020-03-08, and will not fall back on
> >     2020-11-01.
> > We have written a test cases like below for canada yukon timezone. We
> imported
> > new 2020a tz into our environment.
> > Our code seems correct but test cases are failing. So we found that
> there is
> > wrong in Iana tz side.
> > Please check and correct us. This is the below code we have written.
> > @Test
> >     public void doesNotFallBackToMinus8InDawsonNovember2020() {
> >         DateTimeZone timezone = DateTimeZone.forID("America/Dawson");
> >         Instant dayAfter = new DateTime(2020, 11, 2, 0, 0,
> timezone)-------> on
> > 2nd nov 00:00:00
> >                 .withLaterOffsetAtOverlap()
> >                 .toInstant();
> >         Instant day = new DateTime(2020, 11, 1, 0, 0, timezone)------>
> on 1 st
> > nov 00:00:00
> >                 .withLaterOffsetAtOverlap()
> >                 .toInstant();
> >         long dayAfterOffset = timezone.getOffset(dayAfter.getMillis());
> >         int dayAfterHours = (int)
> TimeUnit.MILLISECONDS.toHours(dayAfterOffset);
> >         long offsetOnDay = timezone.getOffset(day.getMillis());
> >         int hoursOnDay = (int)
> TimeUnit.MILLISECONDS.toHours(offsetOnDay);
> >         assertEquals(hoursOnDay, dayAfterHours);  ------->  here we are
> getting
> > error: java.lang.AssertionError: expected:<-7> but was:<-8>
> >     }
> > The above test case according to your update (will not fall back on
> 2020-11-01)
> > is correct. But test case is failing.
> > Could you please clarify us that is there anything wrong from IANA tz.
> > If not how can i write my test case according to that?
>
> For a start, you must always take account of the summer transition times
> forward
> and back.
> Across Canada, times change at Sunday 02:00 local time: in March, as each
> time
> zone hits 02:00, it becomes 03:00; in November, as each time zone hits
> 02:00, it
> becomes 01:00:
>
> $ zdump -Vc2020,2021 Canada/Mountain | sed 's/\(Sun\).*\1/\1/'
> Canada/Mountain  Sun Mar  8 01:59:59 2020 MST isdst=0 gmtoff=-25200
> Canada/Mountain  Sun Mar  8 03:00:00 2020 MDT isdst=1 gmtoff=-21600
> Canada/Mountain  Sun Nov  1 01:59:59 2020 MDT isdst=1 gmtoff=-21600
> Canada/Mountain  Sun Nov  1 01:00:00 2020 MST isdst=0 gmtoff=-25200
>
> so to be sure, you need to check on or after each transition, as you will
> have
> ambiguous times on Sunday in March between 01:00 and 02:00, and in November
> between 02:00 and 03:00.
> In both cases, you could check on or after Sun 03:00.
> Checking at 12:00 noon is often chosen to be safe regardless of actual
> transition times, which could vary from 00:00 to 06:00.
> Similarly, checks are often done on December 31 and June 30 to avoid being
> near
> any northern or southern hemisphere transition dates.
> However in recent years Islamic countries have started to reset summer time
> changes during Ramadan, which can occur any time in the Gregorian calendar.
>
> --
> Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada
>
> This email may be disturbing to some readers as it contains
> too much technical detail. Reader discretion is advised.
> [Data in IEC units and prefixes, physical quantities in SI.]
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mm.icann.org/pipermail/tz/attachments/20200520/78623569/attachment.html>


More information about the tz mailing list