Re: Ada.Calendar.Time_Zones

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Mon, 4 Aug 2008 17:12:38 -0500, Randy Brukardt wrote:

> "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
> news:1rm26vi0mz4sv.1kfhdnswhcrqa.dlg@40tude.net...
>> Does anybody know the meaning of the result returned by UTC_Time_Offset?
> 
> It's as the RM says.

But how to translate what it says into concrete numbers:

   UTC_Time_Offset (Ada.Calendar.Time_Of (2008, 26, 10, 2.5*60.0*60.0)); =?

OK, I am posting that to Ada comments as you suggested.

> It's pretty obvious, though, that there is no way to do this correctly 
> unless the time type is based on UTC (time-zone-less) time. And because of 
> compatibility concerns, the only way to do that is to completely junk 
> Ada.Calendar and start over, duplicating essentially everything. You're 
> probably right that we should have done that, but it would always be a tough 
> sell (lots of people would say that Ada.Calendar is "good enough") -- which 
> is why you need to ask this question directly to the ARG. (And get as many 
> people as possible to support it, too.) I alone could never produce critical 
> mass on this topic.

I don't understand this. Ada.Calendar.Time_Zones, Ada.Calendar.Arithmetic,
Ada.Calendar.Formatting are all new packages. All of them have an
inconsistent semantics, because Time_Of is necessarily inconsistent [*].
Zone offset is simply not a function of the local time. It is of the UTC
time.

--------
* without additional parameters.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de