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Re: [tz] Recent conversions of zones to aliases
by random832＠fastmail.us Oct. 6, 2014

Oct. 6, 2014

On Sat, Oct 4, 2014, at 06:15, Stephen Colebourne wrote: > The key point to remember is that Joda-Time has been running for many > years and has striven very hard to retain backwards compatibility. > Converting aliases to their underlying zone has worked well over many > years, and is far from an unreasonable approach, as it reduces the > effect of older zones such as US-Pacific. The effect of those zones is limited to when the user has actually selected them. For that matter, if aliases were not normalized, you would have _maintained_ backwards compatibility when (in principle - in reality, that was before Joda-Time was even a thing.) the zone name was changed _from_ those older names in the first place. The point of aliases is to limit the impact of changes on users who selected the old name when it was current, by keeping the behavior of their systems the same. "Normalizing" them goes against that principle.

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St Andrews meridian in the 17th century
by Peter Ilieve Oct. 6, 2014

Oct. 6, 2014

Now that we don’t have to think about a possible future Europe/Glasgow zone (postings back in August) for several years at least, here’s a bit of Scottish history to consider instead. St Andrews, on the Fife coast in the east of Scotland, had a meridian line set up some 200 years before Greenwich. Here’s a quote from a press release from the University of St Andrews, who have just created a memorial to mark this line: "The 17th Century Scottish astronomer and scientific pioneer James Gregory laid down a meridian line across the floor of his lab at St Andrews University in 1673, almost 200 years before the Greenwich Meridian was established and arbitrarily adopted as the world’s official prime meridian. "Now St Andrews has recognised Gregory’s remarkable body of work with a permanent public memorial – a solid brass line which follows exactly the line of his meridian and bisects the pavement in South Street, St Andrews.” This story was picked up by The Times and the BBC (and probably others I haven’t seen). As well as the line on the lab floor there was a sighting mark outside a window and a stone marker on a hill 2.4km away. This still exists and is marked on Ordnance Survey maps. Some URLs: The University of St Andrews press release: <http://www.st-andrews.ac.uk/news/archive/2014/title,250213,en.php> BBC piece: <http://www.bbc.co.uk/news/uk-scotland-29474850> The Times piece (which is behind their paywall): <http://www.thetimes.co.uk/tto/news/uk/scotland/article4224136.ece> Map showing St Andrews and Gregory’s Pillar (marked with arrow): <http://www.streetmap.co.uk/idld.srf?X=350994&Y=715496&A=Y&Z=115&lm=1&ax=350…> Peter Ilieve

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[PROPOSED PATCH] * zdump.c (adjusted_yday): Define only if TM_GMTOFF is not defined.
by Paul Eggert Oct. 5, 2014

Oct. 5, 2014

--- zdump.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/zdump.c b/zdump.c index 37a0926..13bbb0e 100644 --- a/zdump.c +++ b/zdump.c @@ -851,8 +851,9 @@ delta(struct tm * newp, struct tm *oldp) return result; } +#ifndef TM_GMTOFF /* Return A->tm_yday, adjusted to compare it fairly to B->tm_yday. - Assume A and B differ by at most one year. */ + Assume A and B differ by at most one year. */ static int adjusted_yday(struct tm const *a, struct tm const *b) { @@ -861,6 +862,7 @@ adjusted_yday(struct tm const *a, struct tm const *b) yday += 365 + isleap_sum(b->tm_year, TM_YEAR_BASE); return yday; } +#endif /* If A is the broken-down local time and B the broken-down UTC for the same instant, return A's UTC offset in seconds, where positive -- 1.9.1

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coding style for tzcode?
by christos＠zoulas.com Oct. 4, 2014

Oct. 4, 2014

Hello, The code used to be 8-tab BSD formatted, and now it seems that 2 space indentantion is being used, or 4 space, or whatever random spacing (sometimes contination lines follow the opening parenthesis of the function above, other times they don't) in both new code and diffs from the old code. If people don't like the current coding style, let's decide on a style, reformat all the code to the new style and keep it consistent. What we have now is making the code unreadable. Thank you! christos

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Timezone for Moscow is -10800 after installing tzdata-2014g
by Alexander Koblov Oct. 4, 2014

Oct. 4, 2014

Hi All! My timezone is Europe/Moscow. After installing tzdata-2014g, tzset sets value for timezone not -14400 as before, but -10800, although time shift will be only in October 26th. Is this the expected behavior, or maybe I don't understand something? Please see below program I use for the test and output from console. Notice, how depends on what version of tzdata is installed value of timezone is different, although current time is the same. My question is: Why tzdata-2014g returns timezone for the Europe/Moscow -10800 (3 hours)? As far as I understand timezone for Moscow should be changed on the night of 25/26 October. Thank you, Alexander. ========== #include <iostream> #include <ctime> #include <cstdlib> using namespace std; int main() { tzset(); //set all 4 DST globals using TZ cout<< "the difference between UTC and the local standard time is: "<<timezone<<endl; cout<<boolalpha; //switch to verbal representation of bools cout<<"DST in effect: "<<(bool) daylight<<endl; cout<<"local standard time code: "<<tzname[0]<<endl; cout<<"local standard time code: "<<tzname[1]<<endl; } ========== ============== // With tzdata-2014g-installed [root@Linux jgm]# ./jtz the difference between UTC and the local standard time is: -10800 DST in effect: true local standard time code: MSK local standard time code: MSD [root@Linux jgm]# date Птн Окт 3 14:43:37 MSK 2014 //Let's downgrade to tzdata-2014b [root@Linux jgm]# yum downgrade tzdata-2014b-1.el6.noarch // skip lines Removed: tzdata.noarch 0:2014g-1.el6 Installed: tzdata.noarch 0:2014b-1.el6 Complete! [root@Linux jgm]# ./jtz the difference between UTC and the local standard time is: -14400 DST in effect: false local standard time code: MSK local standard time code: MSD [root@Linux jgm]# date Птн Окт 3 14:44:05 MSK 2014 //Let's return back to tzdata-2014g [root@Linux jgm]# yum update tzdata //skip lines Updated: tzdata.noarch 0:2014g-1.el6 Complete! [root@Linux jgm]# ./jtz the difference between UTC and the local standard time is: -10800 DST in effect: true local standard time code: MSK local standard time code: MSD [root@Linux jgm]# date Птн Окт 3 14:44:36 MSK 2014 [root@Linux jgm]# ==============

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Handling of uninitialized tm_gmtoff and tm_zone
by random832＠fastmail.us Oct. 2, 2014

Oct. 2, 2014

It is possible that mktime, strftime, etc?, may be called with a struct tm that has not had non-standard members initialized. How does tzcode deal with these cases? (It _looks_ like strftime handles it badly; I can't figure out what, if anything, the mktime implementation does with these members).

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Issue with Jordan timezone
by obulesh kumar Oct. 1, 2014

Oct. 1, 2014

Hi all, I am getting wrong time zone for Jordan in my android device. I am calculating time zone from NITZ information provided by network in Amman country. I am using offset and DST value from NITZ to calculate timezone. Below are the values provided by network on date:15/Jul/2014 OFFSET:10800000 DST:false I am getting from proper timezone for Jordan country in 2013g database version as Asia/Amman. But i am not getting any timezone for Amman country in 2013i database on wards. below is timezone data differences from 2013g to 2013i please find snapshot. [image: Inline image 1] Please help us in resolving this issue. Thanks and Regards, Obulesh

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Aix question
by Donald MacQueen Oct. 1, 2014

Oct. 1, 2014

Hi all, Sorry for the off topic, but does anyone know the procedure for updating tz info on Aix? Google is not my friend today. Thanks in advance. Great work, Paul. -- Donald [|] Joel Cairo: "You always have a very smooth explanation." Sam Spade: "What do you want me to do? Learn to stutter?" - The Maltese Falconn

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Time, Clock, and Calendar Programming In C, by Eric S. Raymond
by random832＠fastmail.us Sept. 30, 2014

Sept. 30, 2014

Eric S. Raymond has written an article about the history of the time.h functions at http://www.catb.org/esr/time-programming/ >From his blog post announcing it (http://esr.ibiblio.org/?p=6311) > The C/UNIX library support for time and calendar programming is a nasty mess of historical contingency. I have grown tired of having to re-learn its quirks every time I’ve had to deal with it, so I’m doing something about that. > > Announcing Time, Clock, and Calendar Programming In C, a document which attempts to chart the historical clutter (so you can ignore it once you know why it’s there) and explain the mysteries. > > What I’ve released is an 0.9 beta version. My hope is that it will rapidly attract some thoroughgoing reviews so I can release a 1.0 in a week or so. More than that, I would welcome a subject matter expert as a collaborator. When I saw it I thought it might be generally interesting to people who subscribe to this list.

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Mehdi Ashrafi
by Mehdi Ashrafi Sept. 29, 2014

Sept. 29, 2014

+989376266654

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