[tz] Did Greenland abolish daylight saving from 2024 on?

Guy Harris gharris at sonic.net
Fri Nov 17 09:00:58 UTC 2023

On Nov 17, 2023, at 12:06 AM, Paul Eggert <eggert at cs.ucla.edu> wrote:

> On 2023-11-16 19:35, Guy Harris wrote:
>> On Nov 16, 2023, at 6:29 PM, Paul Eggert <eggert at cs.ucla.edu> wrote:
>> ...which means that the phrase "Daylight Savings Time" in the POSIX standard refers to something that's not exactly the same as "daylight saving time" as generally understood, i.e. it doesn't necessarily mean "the time that's in effect during summer and possibly some close-to-summer dates in spring and autumn, if clocks are adjusted twice a year, with the clock setting during summer and blah blah blah being ahead of the clock setting during the rest of the year".
> If you're accustomed to the United States then that's indeed what "daylight saving time" has meant. And given the US's influence it's not surprising that the usage is common elsewhere. However, it's not universal, and POSIX and TZDB support the more-general case.

So does POSIX's use of "Daylight Savings Time" mean that "daylight saving time" could either be a time when the clock is turned forward from standard time *or* could *be* standard time, with the clocks being turned *backwards* from standard time for the winter?

Or does it really mean that "daylight saving time" can refer to a period in which the clock is turned *backwards* from standard time?

> The earliest use of negative DST that's recorded in TZDB is Czechoslovakia during winter 1946/1947. That's also the earliest use recorded in the Wikipedia page on negative DST <https://en.wikipedia.org/wiki/Winter_time_(clock_lag)>

The image of the Czechoslovak public journal about that says "zákon o zimnim çase", which Google Translate translates to "winter time law".

Ireland also, as I remember, refers to the time when clocks are turned backwards as "winter time".

The Namibian newspapers used as citations also speak of "winter time".

So, for "standard time is the time in the summer, and clocks are turned backward in the winter" locales, I'm not seeing "daylight saving time" being used either for the period when the clocks are turned forward or for the period when the clocks are turned backward.

>  - a page that you've edited.

And I just edited it again now, to change

	It is a form of [[daylight saving time]] which is the opposite compensation to the summer time (+1, +2).


	It is a form of daylight saving time in which standard time is in effect during summer months, rather than the usual case where standard time is in effect during winter months. 

to clarify it ("the opposite compensation to the summer time" is "opposite" only in the sense that standard time is ahead of non-standard time rather than being behind it - it's not "opposite" in the sense of "the clocks go forward in the winter and backward in the summer", which I see as an equally valid sense of "opposite", and one which I suspect might be the sense most ordinary folk, as opposed to time nerds, would see "opposite" in this case).

(And if anybody claims that it means that daylight saving time is in effect during the winter, I'm going to {{cn}} the heck out of that claim.)

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