Dear Paul,

thanks for the reply.
I have found that there could be some versions already available of the TZ database that could suit my needs.
In order to make a due reply to your suggestions I'd tell something about your responses and I'd like too to submit you some topics that I need to confront with.
The first topic is this: the UNIX date that is supported in many compilers has some limitation in order to the dates preceding Jan 1 1970.
 
The second topic is that some of the compilers you (greatly) list onto your page are not updated at the last version of data, like for instance the Delphi version - right the one I'd like to use - which is - strange to say - includes the data WITHIN the code, that is something really against the most simple rules of Information Technology that is to keep data separated from the code.
So for what this is the solution of this problem I think I will go to some other resource, that is another that I haven't found listed into your page (unless I have resoundingly missed it) that is this one:
https://timezonedb.com/
These great guys provide a MySQL version of the TZ database that seems also up-to-date (I have to check it out but it is promising) and I think you should nicely include this resource into your list (unless, I repeat, I have missed it and this is just in the list already. In this case I apologize for that).
I have an idea about making a software to keep the TZ database updated. I will talk you in the future If I decide to carry on this work.

The third issue is what I have with Italian zones listed in the TZ, because as you correctly state in the description notes of the "europe" file, In Italy there are 3 zones, not only ROME but also Palermo (Sicily island complete) and Cagliari (Sardinia island complete), which differ from each other, also if slightly in time.
How can I add these two zones to the data ?
May I kindly ask you to include these two zones in some the future releases of the database ?

Thanks again for your great help and your invaluable work.

Sergio Bonfiglio









Il giorno gio 30 apr 2020 alle ore 22:39 Paul Eggert <eggert@cs.ucla.edu> ha scritto:
On 4/28/20 8:12 AM, Sergio Bonfiglio wrote:

> I was overwhelmed by the complexity of your database, because it requires
> also external pieces of code to be safely read.

Yes, it's in its own .zi format. Typically I edit it with a text editor so I
suppose that counts as an external piece of code. Most people either do that, or
process it with the code supplied as part of tzdb, or use one of the
already-written tz compilers
<https://data.iana.org/time-zones/tz-link.html#compilers>. Perhaps one of those
will work for you.

> An SQL database could be really "for everyone", because can be queried by
> everything from everywhere by any language.

MariaDB, MySQL, and Oracle Database use tzdb in some form; perhaps they're
already doing something along the lines of what you're asking for.

> If I may make a humble suggestion, a JD date in floating format that equips
> any record with the initial and final date of the rule/event could be of
> great help.

JD should be relatively easy to generate automatically from the existing format.
I doubt whether the source data should have JD directly, though, as JD is
inconvenient for humans and anyway the .zi format is now read by so many
programs that any changes to it would need to be carefully considered and
justified. But JD could be good for database queries, along the lines of your
suggestion.