From: "Nick Roberts" <nickroberts@adaos.worldonline.co.uk>
Subject: Re: Ada, calendar, and daylight savings
Date: Tue, 30 Oct 2001 02:19:51 -0000
Date: 2001-10-30T02:19:51+00:00 [thread overview]
Message-ID: <9rl2s2$u9eai$1@ID-25716.news.dfncis.de> (raw)
In-Reply-To: 3BDD94E6.2030804@acm.org
My suggestion is as follows:
package Ada.Calendar.Worldwide is
type Zoned_Time is private;
-- This type includes the offset from UTC with the actual time.
type Time_Zone_Offset is delta 30*60.0 range -12*60*60.0 .. +12*60*60.0;
-- An offset from UTC, in seconds, as half-hour intervals from -12 to
-- +12 hours. Localtime = TimeUTC + offset.
function Clock return Zoned_Time;
-- Also concurrently ascertains the local offset from UTC.
function Local_Time (Zoned: Zoned_Time) return Time;
-- Returns the local time from a Zoned_Time.
function Time_UTC (Zoned: Zoned_Time) return Time;
-- Returns the time UTC from a Zoned_Time.
function Difference_from_UTC (Zoned: Zoned_Time) return Time_Zone_Offset;
-- Returns the offset from UTC for a Zoned_Time.
function Current_Difference_from_UTC return Time_Zone_Offset;
-- Returns the offset from UTC currently set. Could change at any time.
function To_Zoned (Date: Time;
Difference: Time_Zone_Offset := 0.0)
return Zoned_Time;
private
... -- implementation defined
end Ada.Calendar.Worldwide;
I think this should go into an optional Annex.
I'd like to see the range of Day_Duration extended:
subtype Day_Duration is Duration range 0.0 .. 86_405.0;
in Ada.Calendar in the next revision, to allow for added leap seconds.
--
Nick Roberts
"Corey Minyard" <minyard@acm.org> wrote in message
news:3BDD94E6.2030804@acm.org...
> Marin David Condic wrote:
> ...
> I'm not saying that it needs to use UTC for implementation, but I think
> it at least needs an annex to be able to coordinate time in some way.
> And if it uses daylight savings and timezones, the program needs some
> way to get that information and do translations into different timezones.
>
> > Better that a more sophisticated time package be included as some kind
of
> > annex or optional package. That's why I suggested that it might make a
good
> > candidate for a standard component library.
>
> I'm already working on it. I was just wondering how it should interact
> with Ada.Calendar, and I think I know now.
next prev parent reply other threads:[~2001-10-30 2:19 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-10-28 23:41 Ada, calendar, and daylight savings Corey Minyard
2001-10-28 23:53 ` Larry Kilgallen
2001-10-29 3:44 ` Corey Minyard
2001-10-29 10:17 ` Larry Kilgallen
2001-10-29 14:02 ` Corey Minyard
2001-10-29 14:35 ` Marin David Condic
2001-10-29 2:34 ` Steven Deller
2001-10-29 3:51 ` tmoran
2001-10-29 5:53 ` Corey Minyard
2001-10-29 6:49 ` tmoran
2001-10-29 10:21 ` Larry Kilgallen
2001-10-29 14:18 ` Corey Minyard
2001-10-29 23:15 ` tmoran
2001-10-30 2:07 ` Corey Minyard
2001-10-30 3:11 ` tmoran
2001-11-01 0:13 ` Al Christians
2001-10-30 12:29 ` Larry Kilgallen
2001-10-29 14:48 ` Marin David Condic
2001-10-29 17:41 ` Corey Minyard
2001-10-30 2:19 ` Nick Roberts [this message]
2001-10-30 5:41 ` Al Christians
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