Possible corrections?

Phillip Guerra Phillip.Guerra at nkch.org
Wed Jul 5 15:59:43 UTC 2006

Yes, it would be a help to provide the documentation note.  As one of
the new 'independent' TZ database users (actually developer), I
struggled with the format, until I found the zic doc by accident.  I
didn't have a linux or Unix system available for a resource, so was
trying to use the TZ datastore and convert it for use with MS ASP.Net.
The tab formatting of the file was not consistent, and I remedied that
by parsing it with custom programs that converted it.

I don't really have a preference for which operating system is a
developer or user's choice, but find it really handy to opt for some
kind of datastore structure that is easily translated from one system to
another.  It's just a nice feature to provide.  In this case, the TZ
datastore is the de facto standard for this type of information, not
only for Unix /Linux systems but becoming a standard reference tool for
other systems as well, like it or not.

Now, to be honest all systems have their issues, so it's not really a
question of which O/S is best, but rather how system administrators,
developers, and users can best be helped by standarding on common
refernce information, such as, timezones.  Not an easy task since
globally there is no single historical authoritive source.  However,
since the TZ datastore is the closest I've found, it's the one I'll use,
rather than creating another competing version.  The only thing I'm
doing is making it easier to implement and update for MS systems.  If
only MS would see fit to use a similar tact, then maybe we could get
past the silly issues of converting it.  

All in all, no matter what doc is available, we still depend on
developers to intpreted it correctly.  The only critique I have is the
somewhat confusing aspect of the use of the AT field:

     AT      Gives the time of day at which the rule takes
             effect.  Recognized forms include:

                  2        time in hours
                  2:00     time in hours and minutes
                  15:00    24-hour format time (for times after noon)
                  1:28:14  time in hours, minutes, and seconds
                  -        equivalent to 0

             where hour 0 is midnight at the start of the day,
             and hour 24 is midnight at the end of the day.  Any
             of these forms may be followed by the letter w if
             the given time is local "wall clock" time, s if the
             given time is local "standard" time, or u (or g or
             z) if the given time is universal time; in the
             absence of an indicator, wall clock time is assumed.

It would make lessen the confusion or how to translate this field if the
data were always presented in wall clock time, for us independent types,
Just my 2 cents.
-----Original Message-----
From: Paul Eggert [mailto:eggert at CS.UCLA.EDU] 
Sent: Monday, July 03, 2006 5:30 PM
To: tz at lecserver.nci.nih.gov
Subject: Re: Possible corrections?

Oscar van Vlijmen <ovv at hetnet.nl> writes:

> Sorry for my annoying remarks, but the independent TZ database users 
> keep coming and they apparently get easily confused by the current 
> structure or markup of the data files.

In this particular case, the user had not read the manual, and didn't
even know one existed.  That would be a problem no matter what format we
had chosen.

Perhaps we could forestall future questions like this by starting each
data file with a line saying "The format of this file is described in
<http://www.twinsun.com/man/zic.8.html>."  or something like that.

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