[tz] zdump broken with latest Cairo changes?

Frank Bean macbean at gmail.com
Thu Jun 16 15:46:53 UTC 2016


Just to point out.  Egypt was not observing dst when Ramadan started.
While phones and computers changed, along with international flight
schedules, the official time was still just +2.
On Jun 16, 2016 5:31 PM, "Tim Parenti" <tim at timtimeonline.com> wrote:

> I'm only counting four transitions per year in your output (eight lines)
> and, yes, this is expected.
>
> This year, Ramadan is approximately 5 June to 5 July. Because it moves
> forward ~11 days per year, as it moves earlier in the spring in 2017
> through 2019, it remains wholly within our predicted DST period from
> late-April through late-October. Since Egypt has tended to suspend DST for
> Ramadan in the past, this nominally requires four clock changes per year:
> one to spring forward, one to suspend for Ramadan, one to return after
> Ramadan, and one to fall back.
>
> In 2020–2022, Ramadan does not overlap in this way, and so DST is simply
> delayed by a few weeks until after Ramadan, then in mid-spring, ends. Our
> six-month predicted DST period is then unaffected by Ramadan for several
> years as it moves through the winter months, before it is impinged upon
> once again. In 2036–2038, it merely advances the end date by a few weeks
> while Ramadan is in mid-autumn, but as it progresses forward, beginning in
> 2039, it is once again wholly within the late-April to late-October period,
> and four transitions once again become necessary to reflect Egypt's past
> practices.
>
> Note that, just after tzdata 2016e was released a discussion was started
> as to whether Egypt will actually observe all four transitions in years
> such as 2017–2019 and 2039–2051, or whether they will choose to observe it
> only on one side of the holy month or the other:
> http://mm.icann.org/pipermail/tz/2016-June/023801.html
>
> We don't yet know anything for sure about how this will be handled,
> though… so from historical evidence, this remains our best guess for now.
>
> --
> Tim Parenti
> sent from my Android phone
> On 16 Jun 2016 10:53, "Dave Rolsky" <autarch at urth.org> wrote:
>
>> On Thu, 16 Jun 2016, Dave Rolsky wrote:
>>
>> Here's a snippet of "zdump -v Africa/Cairo" with the latest changes:
>>>
>>
>> I then realized I hadn't installed the latest tzcode. However, even with
>> the latest version I still see 3 changes per year in Africa/Cairo starting
>> in 2039.
>>
>> Is that really what's intended?
>>
>>
>> Cheers,
>>
>> -dave
>>
>> /*============================================================
>> http://VegGuide.org               http://blog.urth.org
>> Your guide to all that's veg      House Absolute(ly Pointless)
>> ============================================================*/
>>
>
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