Yukon to move to year-round PDT
The government of Yukon announced today the cessation of seasonal time changes. "After clocks are pushed ahead one hour on March 8, the territory will remain on 'Pacific Daylight Saving Time'. ... [The government] found 93 per cent of respondents wanted to end seasonal time changes and, of that group, 70 per cent wanted 'permanent Pacific Daylight Saving Time.'" https://www.cbc.ca/news/canada/north/yukon-end-daylight-saving-time-1.548635... Government press release: https://yukon.ca/en/news/yukon-end-seasonal-time-change Interestingly, in the report <https://yukon.ca/sites/yukon.ca/files/engage/engage-eco-seasonal-time-change...> released with today's action, 57% of respondents said that "maintain[ing] time relationships with other jurisdictions" was either very or somewhat important, while only 26% said it was not very or not at all important. Perhaps this might be better treated as "MST", like Arizona, as that is more similar to Saskatchewan's existing use of CST. However, since the press release expresses a preference for "PDT", attached is a proposed patch which calls it that, implemented as UTC-08 +1 hour DST year-round. Since this change doesn't affect timestamps until 2020-11-01, we have a bit of time to determine the preferred representation and/or wait for the relevant legal wording before this necessitates a new release. -- Tim Parenti
Now with a better-formed commit message. -- Tim Parenti On Wed, 4 Mar 2020 at 22:53, Tim Parenti <tim@timtimeonline.com> wrote:
The government of Yukon announced today the cessation of seasonal time changes. "After clocks are pushed ahead one hour on March 8, the territory will remain on 'Pacific Daylight Saving Time'. ... [The government] found 93 per cent of respondents wanted to end seasonal time changes and, of that group, 70 per cent wanted 'permanent Pacific Daylight Saving Time.'"
https://www.cbc.ca/news/canada/north/yukon-end-daylight-saving-time-1.548635...
Government press release: https://yukon.ca/en/news/yukon-end-seasonal-time-change
Interestingly, in the report <https://yukon.ca/sites/yukon.ca/files/engage/engage-eco-seasonal-time-change...> released with today's action, 57% of respondents said that "maintain[ing] time relationships with other jurisdictions" was either very or somewhat important, while only 26% said it was not very or not at all important.
Perhaps this might be better treated as "MST", like Arizona, as that is more similar to Saskatchewan's existing use of CST. However, since the press release expresses a preference for "PDT", attached is a proposed patch which calls it that, implemented as UTC-08 +1 hour DST year-round. Since this change doesn't affect timestamps until 2020-11-01, we have a bit of time to determine the preferred representation and/or wait for the relevant legal wording before this necessitates a new release.
-- Tim Parenti
On 2020-03-05 04:08, Tim Parenti wrote:
+# Beginning 2020-03-08 02:00, use a base offset of -08:00 with 1:00 "permanent" +# DST for Yukon.
I think the current method to deal with "permanent" summer time in tzdb is NOT to use the dst bit; see eg Turkey who are on summer time since 2016. The dst bit is reserved for switches to an alternate offset that is used for less than a year (except for the few historical cases of "war time"). Michael Deckers.
I agree with Michael D. There are four existing zones that are already on permanent UTC-7: America/Dawson_Creek America/Creston America/Fort_Nelson America/Phoenix None of these zones makes use the DST bit. The time zone is displayed year round as MST instead of PDT. I don't think anybody complains about it. I don't see any compelling reason to treat the two Yukon zones (America/Whitehorse & America/Dawson) any differently than the four existing UTC-7 zones. Consistency within the database is more important than trying to match the wording in each government press release and/or bill. Therefore, America/Whitehorse & America/Dawson should be placed on UTC-7 with no DST bit and they should be given a time zone designation of MST. Keep in mind that in the future, it may be necessary to apply the same rules to America/Vancouver and America/Los_Angeles. Note: The Yukon press release uses the term "Pacific Daylight Saving Time" to refer to UTC-7. https://yukon.ca/en/news/yukon-end-seasonal-time-change Note: The British Columbia (BC) government is waiting to see what California does before it drops the bi-annual time change. In the meantime, the government has already passed an amendment for its Interpretation Act; the amendment defines "Pacific Time" as UTC-7. This makes me cringe. https://news.gov.bc.ca/releases/2019PREM0118-002084 https://www.leg.bc.ca/parliamentary-business/legislation-debates-proceedings... -chris -----Original Message----- From: tz <tz-bounces@iana.org> On Behalf Of Michael H Deckers via tz Sent: March 5, 2020 5:59 AM To: tz@iana.org Subject: Re: [tz] Yukon to move to year-round PDT On 2020-03-05 04:08, Tim Parenti wrote:
+# Beginning 2020-03-08 02:00, use a base offset of -08:00 with 1:00 "permanent" +# DST for Yukon.
I think the current method to deal with "permanent" summer time in tzdb is NOT to use the dst bit; see eg Turkey who are on summer time since 2016. The dst bit is reserved for switches to an alternate offset that is used for less than a year (except for the few historical cases of "war time"). Michael Deckers.
On 2020-03-05, at 14:28:20, Chris Walton wrote:
I agree with Michael D.
There are four existing zones that are already on permanent UTC-7: America/Dawson_Creek America/Creston America/Fort_Nelson America/Phoenix None of these zones makes use the DST bit. The time zone is displayed year round as MST instead of PDT. I don't think anybody complains about it.
I don't see any compelling reason to treat the two Yukon zones (America/Whitehorse & America/Dawson) any differently than the four existing UTC-7 zones.
Historic timestamps? -- gil
I agree with Michael D.
There are four existing zones that are already on permanent UTC-7: America/Dawson_Creek America/Creston America/Fort_Nelson America/Phoenix None of these zones makes use the DST bit. The time zone is displayed year round as MST instead of PDT. I don't think anybody complains about it.
I don't see any compelling reason to treat the two Yukon zones (America/Whitehorse & America/Dawson) any differently than the four existing UTC-7 zones.
Historic timestamps? Historic timestamps and their time zone abbreviations do not change. Nobody is suggesting that they should be changed. e.g. America/Dawson already supports all the historical time zone abbreviations that have been used in Yukon Territory since 1900: PDT, PST, YDDT, YDT, YPT, YST , & YWT. The proposed change would force all dates that occur after March 14/2021 to have an MST time zone abbreviation. All dates that occur before March 14/2021 would continue to be displayed with the correct historical time zone abbreviations.
The effect would similar to America/Fort_Nelson that switched from PST/PDT to permanent MST on March 8/2015. $ TZ=America/Fort_Nelson date -d 'Mar 7 2015' Sat Mar 7 00:00:00 PST 2015 $ TZ=America/Fort_Nelson date -d 'Mar 9 2015' Mon Mar 9 00:00:00 MST 2015 -chris
I agree with Michael D.
There are four existing zones that are already on permanent UTC-7: America/Dawson_Creek America/Creston America/Fort_Nelson America/Phoenix None of these zones makes use the DST bit. The time zone is displayed year round as MST instead of PDT. I don't think anybody complains about it.
I don't see any compelling reason to treat the two Yukon zones (America/Whitehorse & America/Dawson) any differently than the four existing UTC-7 zones.
Historic timestamps? Historic timestamps and their time zone abbreviations do not change. Nobody is suggesting that they should be changed. e.g. America/Dawson already supports all the historical time zone abbreviations that have been used in Yukon Territory since 1900: PDT, PST, YDDT, YDT, YPT, YST , & YWT. The proposed change would force all dates that occur after March 14/2021 to have an MST time zone abbreviation. All dates that occur before March 14/2021 would continue to be displayed with the correct historical time zone abbreviations. Correction: the change takes place this upcoming weekend (March 8/2020). It is not March 14/2021 as I indicated in my previous e-mail. -chris
On 2020-03-05 16:10, Chris Walton wrote:
I agree with Michael D.
There are four existing zones that are already on permanent UTC-7: America/Dawson_Creek America/Creston America/Fort_Nelson America/Phoenix None of these zones makes use the DST bit. The time zone is displayed year round as MST instead of PDT. I don't think anybody complains about it.
I don't see any compelling reason to treat the two Yukon zones (America/Whitehorse & America/Dawson) any differently than the four existing UTC-7 zones.
Historic timestamps? Historic timestamps and their time zone abbreviations do not change. Nobody is suggesting that they should be changed. e.g. America/Dawson already supports all the historical time zone abbreviations that have been used in Yukon Territory since 1900: PDT, PST, YDDT, YDT, YPT, YST , & YWT. The proposed change would force all dates that occur after March 14/2021 to have an MST time zone abbreviation. All dates that occur before March 14/2021 would continue to be displayed with the correct historical time zone abbreviations. Correction: the change takes place this upcoming weekend (March 8/2020). It is not March 14/2021 as I indicated in my previous e-mail.
The change takes place in November; this weekend proceeds as normal. This weekend, Canadian time zones change to [PMCEAN]DT/HA[PRCEAT](fr-CA), except possibly areas near the AB/BC border, in SK except AB/SK border, and QC E of 63W, which may or may not use abbreviations MST/-7, CST/-6, AST/HNA/-4 locally, rather than PDT/-7, MDT/-6, and EDT/HAE/-4 as used in the adjacent areas, which appears to be the official preference of the NRC standards body, and thus the Canadian government: https://nrc.canada.ca/en/certifications-evaluations-standards/canadas-offici... https://nrc.canada.ca/en/certifications-evaluations-standards/canadas-offici... which appears to consider that all of Canada changes to DST time zones, but some areas keep the same UTC offset. -- 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.
From: tz <tz-bounces@iana.org> On Behalf Of Brian Inglis Sent: March 6, 2020 5:07 PM To: tz@iana.org Subject: Re: [tz] Yukon to move to year-round PDT
On 2020-03-05 16:10, Chris Walton wrote:
I agree with Michael D.
There are four existing zones that are already on permanent UTC-7: America/Dawson_Creek America/Creston America/Fort_Nelson America/Phoenix None of these zones makes use the DST bit. The time zone is displayed year round as MST instead of PDT. I don't think anybody complains about it.
I don't see any compelling reason to treat the two Yukon zones (America/Whitehorse & America/Dawson) any differently than the four existing UTC-7 zones.
Historic timestamps? Historic timestamps and their time zone abbreviations do not change. Nobody is suggesting that they should be changed. e.g. America/Dawson already supports all the historical time zone abbreviations that have been used in Yukon Territory since 1900: PDT, PST, YDDT, YDT, YPT, YST , & YWT. The proposed change would force all dates that occur after March 14/2021 to have an MST time zone abbreviation. All dates that occur before March 14/2021 would continue to be displayed with the correct historical time zone abbreviations. Correction: the change takes place this upcoming weekend (March 8/2020). It is not March 14/2021 as I indicated in my previous e-mail.
The change takes place in November; this weekend proceeds as normal. OK. The wording in the new release says "The spring 2020 seasonal time change will go ahead as planned this Sunday, March 8. After that, Yukon will remain on Pacific Daylight Saving Time." Thus any new time zone rules don't technically need to take effect until Nov 1/2020. A change in November could be handled similarly to the America/Grand_Turk change that took place on Nov 1 2015 in which: a) the time of day did not change (i.e. nobody had to reset their clocks or watches). b) time zone abbreviation flipped from EDT to AST. $ zdump -v America/Grand_Turk | grep '2015 UTC = Sun Nov 1' America/Grand_Turk Sun Nov 1 05:59:59 2015 UTC = Sun Nov 1 01:59:59 2015 EDT isdst=1 gmtoff=-14400 America/Grand_Turk Sun Nov 1 06:00:00 2015 UTC = Sun Nov 1 02:00:00 2015 AST isdst=0 gmtoff=-14400 -chris
On 2020-03-07 08:32, Chris Walton wrote:
From: tz <tz-bounces@iana.org> On Behalf Of Brian Inglis Sent: March 6, 2020 5:07 PM To: tz@iana.org Subject: Re: [tz] Yukon to move to year-round PDT
On 2020-03-05 16:10, Chris Walton wrote:
I agree with Michael D.
There are four existing zones that are already on permanent UTC-7: America/Dawson_Creek America/Creston America/Fort_Nelson America/Phoenix None of these zones makes use the DST bit. The time zone is displayed year round as MST instead of PDT. I don't think anybody complains about it.
I don't see any compelling reason to treat the two Yukon zones (America/Whitehorse & America/Dawson) any differently than the four existing UTC-7 zones.
Historic timestamps? Historic timestamps and their time zone abbreviations do not change. Nobody is suggesting that they should be changed. e.g. America/Dawson already supports all the historical time zone abbreviations that have been used in Yukon Territory since 1900: PDT, PST, YDDT, YDT, YPT, YST , & YWT. The proposed change would force all dates that occur after March 14/2021 to have an MST time zone abbreviation. All dates that occur before March 14/2021 would continue to be displayed with the correct historical time zone abbreviations. Correction: the change takes place this upcoming weekend (March 8/2020). It is not March 14/2021 as I indicated in my previous e-mail.
The change takes place in November; this weekend proceeds as normal. OK. The wording in the new release says "The spring 2020 seasonal time change will go ahead as planned this Sunday, March 8. After that, Yukon will remain on Pacific Daylight Saving Time." Thus any new time zone rules don't technically need to take effect until Nov 1/2020. A change in November could be handled similarly to the America/Grand_Turk change that took place on Nov 1 2015 in which: a) the time of day did not change (i.e. nobody had to reset their clocks or watches). b) time zone abbreviation flipped from EDT to AST. $ zdump -v America/Grand_Turk | grep '2015 UTC = Sun Nov 1' America/Grand_Turk Sun Nov 1 05:59:59 2015 UTC = Sun Nov 1 01:59:59 2015 EDT isdst=1 gmtoff=-14400 America/Grand_Turk Sun Nov 1 06:00:00 2015 UTC = Sun Nov 1 02:00:00 2015 AST isdst=0 gmtoff=-14400 -chris
As one of the boots on the ground (living in America/Whitehorse), I'd say that seeing MST as the Yukon time zone would be very confusing, and might meet strong resistance, given that we've been aligned with BC (PST/PDT) for a generation. Furthermore, if BC also switches to permanent MST/PDT then you would be facing a far more populous region likely completely unenamoured with being lumped in with Alberta. Perhaps the solution for America/Whitehorse and America/Dawson is to resurrect YST (-07). Would that be an option? I'll write to the minister to see what he says (it's a small town :) Erik
On 3/7/20 4:50 PM, Erik wrote:
Perhaps the solution for America/Whitehorse and America/Dawson is to resurrect YST (-07). Would that be an option?
Yes, that would be a very nice idea.
I'll write to the minister to see what he says (it's a small town :)
Thanks. PS. Whitehorse (pop. 25,085) is more than 5⨯ the size of the town I grew up in.
From: tz <tz-bounces@iana.org> On Behalf Of Paul Eggert Sent: March 7, 2020 9:11 PM To: Erik <vy1ewb@gmail.com> Cc: Time zone mailing list <tz@iana.org> Subject: Re: [tz] Yukon to move to year-round PDT
On 3/7/20 4:50 PM, Erik wrote:
Perhaps the solution for America/Whitehorse and America/Dawson is to resurrect YST (-07). Would that be an option?
Yes, that would be a very nice idea. Yukon Standard Time (YST) is officially UTC-9 as defined in section 35 of the Canada's federal Interpretation Act. https://laws-lois.justice.gc.ca/eng/acts/i-21/page-4.html#h-279462 YST cannot be arbitrarily redefined to UTC-7 by anybody on this mailing list; nor can it be redefined by the Yukon government. Furthermore, I think that redefining YST is a bad idea because it would create ambiguity when dealing with old and new time stamps. YST(UTC-9) has been used as recently as 1983 in Alaska and 1973 in Yukon. -chris
On 2020-03-07 19:12, Chris Walton wrote:
From: tz <tz-bounces@iana.org> On Behalf Of Paul Eggert Sent: March 7, 2020 9:11 PM To: Erik <vy1ewb@gmail.com> Cc: Time zone mailing list <tz@iana.org> Subject: Re: [tz] Yukon to move to year-round PDT
On 3/7/20 4:50 PM, Erik wrote:
Perhaps the solution for America/Whitehorse and America/Dawson is to resurrect YST (-07). Would that be an option?
Yes, that would be a very nice idea. Yukon Standard Time (YST) is officially UTC-9 as defined in section 35 of the Canada's federal Interpretation Act. https://laws-lois.justice.gc.ca/eng/acts/i-21/page-4.html#h-279462 YST cannot be arbitrarily redefined to UTC-7 by anybody on this mailing list; nor can it be redefined by the Yukon government. Furthermore, I think that redefining YST is a bad idea because it would create ambiguity when dealing with old and new time stamps. YST(UTC-9) has been used as recently as 1983 in Alaska and 1973 in Yukon. -chris
Interesting, but then it seems that the quoted act has been flagrantly violated for 47 years as the Yukon observed PST instead of YST (despite the act being updated in 2015)! Furthermore, you would run afoul of that same piece of legislation in assigning MST to the Yukon :) It seems that it would require an amendment of this act to resolve the issue either way, since no proposed solution conforms to the definitions. Cheers, Erik p.s. Perhaps this legislation is why Linux installers, until recently, listed the long-unused Yukon Time as an option - I always wondered why...
Date: Sun, 8 Mar 2020 03:12:57 +0000 From: Chris Walton <Chris.Walton@telus.com> Message-ID: <8d0180be1f9648b09103043e21b0195a@BTWP000240.corp.ads> | Yukon Standard Time (YST) is officially UTC-9 as defined in section 35 | of the Canada's federal Interpretation Act. According to that, that is unless it has been modified by a proclamation by the Govenor in Council (and since Yukon apparantly hasn't been using UTC-9 for some time, I'd suspect that has probably happened). But that act doesn't mention "YST" at all, nor does it in any way prevent anyone from using that abbreviation (or acronym, or whatever it is really called) for any purpose, with any meaning they like. If I want to use it to mean Young Sexy Thing there's nothing there to stop me. So: | YST cannot be arbitrarily redefined to UTC-7 by anybody on | this mailing list; Of course it can, we can use whatever abbreviation that we consider appropriate. I have no opinion on what that should be, I'm nowhere near Canada, but there is absolutely nothing there that requires or prohibits anyone from doing anything at all - it is simply an interpretation act, which specifies what certain phrases mean when used in other acts (in this case "standard time"). | nor can it be redefined by the Yukon government. Whether it is within their (current) power to choose the time in which they operate I have no idea, but there is certainly nothing in that act which prohibits them from doing anything they like. Whether they have the ability to alter what standard time means for the purposes of federal (Canadian) acts & proclomations, I have no idea - that could have been delegated to them by some other instrument, or not. But there's nothing in that particular act which limits whatever powers the provinces & territories might have to legislate with respect to how time should be counted for the purposes of those matters that are under their control. Whether there is something elsewhere, I have no idea - I have never bothered to research how the Canadian legislative system works. But if the Yukon territory shifts its clocks to UTC-7 year round, then I'd expect (if still required) a procolamation from the Govenor in Council stating that would be issued (unless for some obscure reason some other part of Canada actually cares what the clocks in the Yukon say, which frankly, I doubt). | Furthermore, I think that redefining YST is a bad idea because it | would create ambiguity The three(or whatever) letter TZ abbreviations are inherently ambiguous. Anyone who ever attempts to use them for any purpose whatever, other than giving a warm fuzzy feeling to humans deserves no sympathy at all when whatever they are doing fails miserably. | when dealing with old and new time stamps. When dealing with time stamps, we know what the offset from UTC was from the date/time recorded, if we know in which timezone the timestamp applies (for which the abbreviation is not sufficient). That's what this project's data is all about, and why we collect all that historic information (rather than relying upon something deficient like a POSIX TZ string). I understand that people have fixed opinions on what particular timezones should be called, and what offset from UTC they should represent, but things change - none of this has existed for very long (archeologically speaking) and what we consider to be something fixed and unchangeable today might be entirely different tomorrow. PST might become UTC-7, YST might become UTC-7 as well - that we used to believe they were UTC-8 and UTC-9 respectively means nothing at all. kre
On 2020-03-08 07:35, Robert Elz wrote:
Date: Sun, 8 Mar 2020 03:12:57 +0000 From: Chris Walton <Chris.Walton@telus.com> Message-ID: <8d0180be1f9648b09103043e21b0195a@BTWP000240.corp.ads>
| Yukon Standard Time (YST) is officially UTC-9 as defined in section 35 | of the Canada's federal Interpretation Act.
According to that, that is unless it has been modified by a proclamation by the Govenor in Council (and since Yukon apparantly hasn't been using UTC-9 for some time, I'd suspect that has probably happened).
As that page states that it is current to date, but last updated in 2015, it should be valid as of any changes made for the 2007 NA switch date changes, and obviously does not dictate what practices occur within provinces and territories.
But that act doesn't mention "YST" at all, nor does it in any way prevent anyone from using that abbreviation (or acronym, or whatever it is really called) for any purpose, with any meaning they like. If I want to use it to mean Young Sexy Thing there's nothing there to stop me.
So: | YST cannot be arbitrarily redefined to UTC-7 by anybody on | this mailing list;
Of course it can, we can use whatever abbreviation that we consider appropriate. I have no opinion on what that should be, I'm nowhere near Canada, but there is absolutely nothing there that requires or prohibits anyone from doing anything at all - it is simply an interpretation act, which specifies what certain phrases mean when used in other acts (in this case "standard time").
| nor can it be redefined by the Yukon government.
Whether it is within their (current) power to choose the time in which they operate I have no idea, but there is certainly nothing in that act which prohibits them from doing anything they like.
Whether they have the ability to alter what standard time means for the purposes of federal (Canadian) acts & proclomations, I have no idea - that could have been delegated to them by some other instrument, or not. But there's nothing in that particular act which limits whatever powers the provinces & territories might have to legislate with respect to how time should be counted for the purposes of those matters that are under their control. Whether there is something elsewhere, I have no idea - I have never bothered to research how the Canadian legislative system works.
For the 2007 NA switch date changes, each province and territory had to change its legislation, and tz db zone info was not updated until a province or territory enacted their legislation (see archives about 2006).
But if the Yukon territory shifts its clocks to UTC-7 year round, then I'd expect (if still required) a procolamation from the Govenor in Council stating that would be issued (unless for some obscure reason some other part of Canada actually cares what the clocks in the Yukon say, which frankly, I doubt).
| Furthermore, I think that redefining YST is a bad idea because it | would create ambiguity
The three(or whatever) letter TZ abbreviations are inherently ambiguous. Anyone who ever attempts to use them for any purpose whatever, other than giving a warm fuzzy feeling to humans deserves no sympathy at all when whatever they are doing fails miserably.
| when dealing with old and new time stamps.
When dealing with time stamps, we know what the offset from UTC was from the date/time recorded, if we know in which timezone the timestamp applies (for which the abbreviation is not sufficient). That's what this project's data is all about, and why we collect all that historic information (rather than relying upon something deficient like a POSIX TZ string).
I understand that people have fixed opinions on what particular timezones should be called, and what offset from UTC they should represent, but things change - none of this has existed for very long (archeologically speaking) and what we consider to be something fixed and unchangeable today might be entirely different tomorrow. PST might become UTC-7, YST might become UTC-7 as well - that we used to believe they were UTC-8 and UTC-9 respectively means nothing at all.
Current official practice seems to be to use daylight saving time zone names in summer, and standard time zone names in winter. Practice on the ground may use those in effect in adjacent areas, as these practices are usually for ease of commerce and/or communication, or maintain use of the standard time zone name year round. I don't believe we currently have any documented information about usage in summer in NE BC, SK, or QC E of 65 W. -- 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.
On 3/9/20 1:24 PM, Brian Inglis wrote:
Current official practice seems to be to use daylight saving time zone names in summer, and standard time zone names in winter.
Are you saying that people in Dawson Creek, Ft Nelson and Creston consistently say that they observe PDT in winter and MST in summer? My impression is that they don't much care what you call it, so long as you get the right clock setting. The press release announcing the 2015 for Fort Nelson <https://www.northernrockies.ca/assets/Home/Press~Releases/NRRM_Time_Change_P...>, for example, says "The Northern Rockies Regional Municipality has resolved to remain on Mountain Standard Time (Pacific Daylight Time) throughout the entire year". As I see it, the options compatible with current POSIX are the equivalent of: * TZ='MST7' (MST all year, as standard time) * TZ='PDT7' (PDT all year, as standard time) * TZ='MST7PDT7,M3.2.0,M11.1.0' (MST in winter as standard time, PDT in summer as daylight saving time, and both are UTC -7) None of these are entirely satisfactory. The first option is what we've been using in Dawson Creek etc., which is why it's in the draft tzdata now for Yukon.
On 2020-03-09 14:46, Paul Eggert wrote:
On 3/9/20 1:24 PM, Brian Inglis wrote:
Current official practice seems to be to use daylight saving time zone names in summer, and standard time zone names in winter.
Are you saying that people in Dawson Creek, Ft Nelson and Creston consistently say that they observe PDT in winter and MST in summer? My impression is that they don't much care what you call it, so long as you get the right clock setting. The press release announcing the 2015 for Fort Nelson <https://www.northernrockies.ca/assets/Home/Press~Releases/NRRM_Time_Change_P...>, for example, says "The Northern Rockies Regional Municipality has resolved to remain on Mountain Standard Time (Pacific Daylight Time) throughout the entire year".
That seems to be the official *federal* position as in: https://nrc.canada.ca/en/certifications-evaluations-standards/canadas-offici... and if they update those maps, Winter Time Zones will show Yukon (and possibly adjacent arctic areas) in yellow.
As I see it, the options compatible with current POSIX are the equivalent of:
* TZ='MST7' (MST all year, as standard time)
* TZ='PDT7' (PDT all year, as standard time)
* TZ='MST7PDT7,M3.2.0,M11.1.0' (MST in winter as standard time, PDT in summer as daylight saving time, and both are UTC -7)
None of these are entirely satisfactory. The first option is what we've been using in Dawson Creek etc., which is why it's in the draft tzdata now for Yukon.
As I said we don't seem to have heard from any locals in variant areas about actual practices. -- 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.
On Thu, 5 Mar 2020 at 16:28, Chris Walton <Chris.Walton@telus.com> wrote:
There are four existing zones that are already on permanent UTC-7: America/Dawson_Creek America/Creston America/Fort_Nelson America/Phoenix None of these zones makes use the DST bit. The time zone is displayed year round as MST instead of PDT. I don't think anybody complains about it.
I don't see any compelling reason to treat the two Yukon zones (America/Whitehorse & America/Dawson) any differently than the four existing UTC-7 zones.
A good point. I had forgotten about the smaller areas already observing -07 year-round. So, this new proposed patch, attached, affects abbreviations from this coming weekend. But timestamps remain unaffected until November. -- Tim Parenti
On 3/5/20 2:53 PM, Tim Parenti wrote:
So, this new proposed patch, attached, affects abbreviations from this coming weekend. But timestamps remain unaffected until November.
Thanks, I installed that into the development version. I also prefer the "MST" abbreviation for what is now effectively mountain standard time.
On Thu, 5 Mar 2020, Paul Eggert wrote:
On 3/5/20 2:53 PM, Tim Parenti wrote:
So, this new proposed patch, attached, affects abbreviations from this coming weekend. But timestamps remain unaffected until November.
Thanks, I installed that into the development version. I also prefer the "MST" abbreviation for what is now effectively mountain standard time.
Doesn't such a position, however, fly in the face of the "boots on the ground" approach we've taken in other situations? I remember when we removed a bunch of abbreviations that had no basis in fact. In this case it seems we're trying to dictate what their abbreviation they should use, and flying in the face of what we should reasonably expect those boots (and the folks attached to them) to use. +--------------------+--------------------------+-----------------------+ | Paul Goyette | PGP Key fingerprint: | E-mail addresses: | | (Retired) | FA29 0E3B 35AF E8AE 6651 | paul@whooppee.com | | Software Developer | 0786 F758 55DE 53BA 7731 | pgoyette@netbsd.org | +--------------------+--------------------------+-----------------------+
On 3/5/20 5:31 PM, Paul Goyette wrote:
Doesn't such a position, however, fly in the face of the "boots on the ground" approach we've taken in other situations?
Yes it does. But then, we consistently flew in the face of that approach in the past when this situation arose, so at least we'd be *consistently* inconsistent. (There is a technical obstacle to having a time zone observe DST indefinitely, as this can't be implemented via POSIX TZ strings on many platforms.) Another possibility would be to put "-07" into the database for now, until we find out what abbreviation (if any) people actually use once the timestamps diverge in November. If people end up using "PDT" next winter in Yukon we can put that into the database, even though it will be odd that it's "PDT" even though the is_dst flag will be 0 due to the abovementioned technical obstacle. I've been fearing this technical snafu for many months as the "permanent DST" movement has gained steam in North America.
On Mar 5, 2020, at 8:45 PM, Paul Eggert <eggert@cs.ucla.edu> wrote:
[EXTERNAL EMAIL] On 3/5/20 5:31 PM, Paul Goyette wrote:
Doesn't such a position, however, fly in the face of the "boots on the ground" approach we've taken in other situations?
Yes it does. But then, we consistently flew in the face of that approach in the past when this situation arose, so at least we'd be *consistently* inconsistent. (There is a technical obstacle to having a time zone observe DST indefinitely, as this can't be implemented via POSIX TZ strings on many platforms.)
Another possibility would be to put "-07" into the database for now, until we find out what abbreviation (if any) people actually use once the timestamps diverge in November. If people end up using "PDT" next winter in Yukon we can put that into the database, even though it will be odd that it's "PDT" even though the is_dst flag will be 0 due to the abovementioned technical obstacle.
I've been fearing this technical snafu for many months as the "permanent DST" movement has gained steam in North America.
I view isdst as valid only if there are two time offsets, active at different times according to something resembling a rule. Normally "isdst" means summer time, with one or two oddball exceptions. But when only one rule is in effect year-round, it doesn't make sense to set the "non-standard" flag, which is what "isdst" is. So never mind the "technical obstacle"; set is_dst 0 as a matter of principle no matter whether POSIX justifies it or not. paul
From: tz <tz-bounces@iana.org> On Behalf Of Paul.Koning@dell.com
On Mar 5, 2020, at 8:45 PM, Paul Eggert <eggert@cs.ucla.edu> wrote:
[EXTERNAL EMAIL] On 3/5/20 5:31 PM, Paul Goyette wrote:
Doesn't such a position, however, fly in the face of the "boots on the ground" approach we've taken in other situations?
Yes it does. But then, we consistently flew in the face of that approach in the past when this situation arose, so at least we'd be *consistently* inconsistent. (There is a technical obstacle to having a time zone observe DST indefinitely, as this can't be implemented via POSIX TZ strings on many platforms.)
Another possibility would be to put "-07" into the database for now, until we find out what abbreviation (if any) people actually use once the timestamps diverge in November. If people end up using "PDT" next winter in Yukon we can put that into the database, even though it will be odd that it's "PDT" even though the is_dst flag will be 0 due to the abovementioned technical obstacle.
I've been fearing this technical snafu for many months as the "permanent DST" movement has gained steam in North America.
I view isdst as valid only if there are two time offsets, active at different times according to something resembling a rule. Normally "isdst" means summer time, with one or two oddball exceptions. But when only one rule is in effect year-round, it doesn't make sense to set the "non-standard" flag, which is what "isdst" is.
So never mind the "technical obstacle"; set is_dst 0 as a matter of principle no matter whether POSIX justifies it or not.
I think everyone is in agreement on setting is_dst to 0. Good. I don't agree with the idea of using "-07" as the time zone abbreviation with a "wait and see" approach. I fear it would lead to legibility problems in such places as weather forecasts. E.g. notice how the current time zone abbreviation is prominently displayed in a time stamp on Environment Canada's weather forecast pages for Dawson City YT and Fort Nelson BC. https://weather.gc.ca/city/pages/yt-6_metric_e.html https://weather.gc.ca/city/pages/bc-83_metric_e.html. I would be very surprised if these pages did not pull the time zone abbreviations directly from tzdata time zone files. The current time stamp of "8:00 PM MST Thursday 5 March 2020" is very clear and very readable. If the same time stamp were to show up as "8:00 PM -07 Thursday 5 March 2020", I would consider it to be confusing to the average Canadian. And I still don't agree with the idea of using "PDT" even though it would align with the Yukon government's press release. We have to consider that: America/Dawson_Creek, America/Fort_Nelson, America/Whitehorse, and America/Dawson together form a contiguous area within a single country (Canada). Starting next Sunday, the entire area will be on permanent UTC-7. America/Dawson_Creek has been using the MST time zone abbreviation since 1972. America/Fort_Nelson has been using the "MST" time zone abbreviation since 2015. It would make no sense at all to apply a different time zone abbreviation (either "-07" or "PDT") to America/Dawson or America/Whitehorse; doing so would create a permanent confusion and inconsistency that would never go away. If we stick with "MST" there may be a few people that are confused for a few days, but that confusion will quickly pass. -chris
On 2020-03-05 22:53, Tim Parenti wrote:
+ -8:00 Canada P%sT 2020 Mar 8 2:00 + -7:00 - MST
The boots on the ground seem to agree that the change is on Nov 01. The abbreviation currently is PDT, and tzdb should record this. So the patch has to be + -8:00 Canada P%sT 2020 Nov 1 2:00 + -7:00 - MST (or whatever abbreviation will be chosen). Michael Deckers.
participants (10)
-
Brian Inglis -
Chris Walton -
Erik -
Michael H Deckers -
Paul Eggert -
Paul Gilmartin -
Paul Goyette -
Paul.Koning＠dell.com -
Robert Elz -
Tim Parenti