[tz] Hard copy of TZdata2023?

[Alexandre Petrescu]

Le 20/10/2023 à 21:46, Brian Inglis via tz a écrit :
> On 2023-10-20 11:27, Alexandre Petrescu via tz wrote:
>> Le 15/10/2023 à 02:28, natyaveda via tz a écrit :
>>> Hey, are you aware of any printable or hard copy (paper) 
>>> publications of your Time-Zone database in a complete or 
>>> semi-complete form?
>>> Perhaps this has been produced by someone in the astrology community?
>>> I'm basically looking to see if its possible to get the rights to 
>>> include parts of such a publication in a publication of my own.  I 
>>> doubt one exists that includes all the info for every city in the 
>>> world in a single publication, but I'm looking to see if it does and 
>>> how large it might be.
>>> What I have in mind is something that lists information pretty much 
>>> exactly as its presented in the tables for the "Detailed time zone 
>>> and clock changes" available on timeanddate.com (minus everything 
>>> outside the tables):
>>> <https://www.timeanddate.com/time/zone/canada/vancouver>
>
> > I am looking to obtain approximately the same.
>> The full database might be too much to print and read. But a concise 
>> form
>> of it, on an A4 or letter sized paper, might be useful. It should be
>> updateable easily, every few months or so. It should contain the 
>> capitals and
>> major cities worldwide. Should not contain the past history info. Should
>> list the names in alphabetical order, and with several spellings (local
>> spelling first). It should tell the date of the next few DST changes. 
>> Should
>> be printed in a large font. Should be used when Internet is not 
>> available. > Other than that hard copy, I am also interested to be 
>> notified by email
>> about the single next DST change that will happen at a site worldwide 
>> (not
>> only at my place). For example, I think now the next DST change (no 
>> DST) is
>> going to happen in Europe in November, but not sure whether there are 
>> others
>> before that.
> I have defined a zdump alias for interactive use (below) which 
> searches backwards for the first transition in the given zone (or 
> local time) from this year,

Thanks for the zdump commands.  I am interested very much in that 
-Vc2023,2024 option.

But the names of the timezones are a much more difficult matter. The 
names of cities, countries or regions are so difficult to identify.  It 
comes down to manually grepping 'city' to identify the continent file, 
and then vi to search for the Zone.  The principal difficulty in this is 
to write down 'city' in the right way; and that way is not necessarily 
the correct way of writing 'city'.  There is an additional difficulty in 
identifying _which_ city is representative for a particular place whose 
time and DST I need, but that is a geography problem.

When I came here I thought it would be easy to find the timezones and 
DSTs of some places, but it's not that simple.

What stays good is that zdump command, provided I know the correct Zone.

Thanks for the files and commands!

Alex

> displaying them up to the start of next year (whose data is not 
> included in any output), which you may be able to adapt by iterating 
> thru all zones of interest, which could just be symlinks to zoneinfo 
> in some directory as in the examples at the top of the shell commands 
> and output.
>
> And seriously *hardcopy*, in this century (other than for tax backups, 
> which are still based on Roman technology)?!
> At least generate markdown or html which can be displayed locally in a 
> browser, or converted to a digital document using pandoc, htmldoc, or 
> similar.
> Then you can run this generation process whenever a new tz release is 
> detected automatically, so it is always up to date.
>
> # zdump interesting zones using alias or script then post-process
> $ ln -st ./interested/ /usr/share/zoneinfo/Europe/Brussels ... # 
> symlink zones
> $ for tz in ./interested/*; do zdump $tz; done | process    # output 
> zones
>
> $ which zdump    # interactive alias
> zdump ()
> {
>     local z=${@:-${TZ:-/etc/localtime}} y=$(date +%Y);
>     local e=$(($y+1)) b p l t;
>
>     for b in $y 1970 1900 1752;
>     do
>         range=-Vc$b,$e;
>         p=$(command /usr/bin/zdump $range $z);
>         [ -n "$p" ] && break;
>     done;
>
>     l=${p##*'
> '};
>     t=${l##*[012][0-9]:[0-5][0-9]:[0-6][0-9] };
>     b=${t:0:4};
>
>     if [ -n "$b" ]; then
>         range=-Vc$b,$e;
>         [ $b -lt $y ] && p=$(command /usr/bin/zdump $range $z);
>     else
>         range='';
>         p=$(command /usr/bin/zdump $range $z);
>     fi;
>
>     [ -n "$range" ] && echo zdump $range $z;
>
>     echo "$p"
> }
>
> # zdump alias example outputs
>
> $ zdump Europe/Brussels
> zdump -Vc2023,2024 Europe/Brussels
> Europe/Brussels  Sun Mar 26 00:59:59 2023 UT = Sun Mar 26 01:59:59 
> 2023 CET isdst=0 gmtoff=3600
> Europe/Brussels  Sun Mar 26 01:00:00 2023 UT = Sun Mar 26 03:00:00 
> 2023 CEST isdst=1 gmtoff=7200
> Europe/Brussels  Sun Oct 29 00:59:59 2023 UT = Sun Oct 29 02:59:59 
> 2023 CEST isdst=1 gmtoff=7200
> Europe/Brussels  Sun Oct 29 01:00:00 2023 UT = Sun Oct 29 02:00:00 
> 2023 CET isdst=0 gmtoff=3600
>
> $ zdump
> zdump -Vc2023,2024 America/Edmonton
> America/Edmonton  Sun Mar 12 08:59:59 2023 UT = Sun Mar 12 01:59:59 
> 2023 MST isdst=0 gmtoff=-25200
> America/Edmonton  Sun Mar 12 09:00:00 2023 UT = Sun Mar 12 03:00:00 
> 2023 MDT isdst=1 gmtoff=-21600
> America/Edmonton  Sun Nov  5 07:59:59 2023 UT = Sun Nov  5 01:59:59 
> 2023 MDT isdst=1 gmtoff=-21600
> America/Edmonton  Sun Nov  5 08:00:00 2023 UT = Sun Nov  5 01:00:00 
> 2023 MST isdst=0 gmtoff=-25200
>
> $ zdump America/Regina
> zdump -Vc1960,2024 America/Regina
> America/Regina  Sun Apr 24 08:59:59 1960 UT = Sun Apr 24 01:59:59 1960 
> MST isdst=0 gmtoff=-25200
> America/Regina  Sun Apr 24 09:00:00 1960 UT = Sun Apr 24 03:00:00 1960 
> CST isdst=0 gmtoff=-21600
>