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From: sjw <simon.j.wright@mac.com>
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Subject: Re: Platform independent calendar
Date: Sun, 7 Dec 2008 23:17:23 -0800 (PST)
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Date: 2008-12-07T23:17:23-08:00
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On Dec 7, 11:56=A0pm, "Jeffrey R. Carter"
<spam.jrcarter....@spam.acm.org> wrote:
> Mike H wrote:
> > I am working (solo) on a signalling related application for a UK
> > preserved railway. The system needs to be as near to totally platform
> > independent as possible. As I see it, this rules out use of package
> > Calendar.
>
> > Rather than re-invent a wheel, I would prefer to use a pre-existing
> > solution and would be grateful for suggestions.
>
> You should probably use Ada.Real_Time rather than Ada.Calendar for such a=
n
> application.

At least Ada.Calendar refers to externally-visible time (even though
there may be problems related to eg time zones which are not likely to
be a bother in Mike's application).

I would have thought Real_Time had even less applicability in a
distributed system than Calendar. Real_Time doesn't refer to real time
such as you might read on your watch, it's related to hard real time
control systems; are your signal requirements like that?

In (older?) GNATs, Real_Time and Calendar were the same, I think this
may have changed now (hope so, cos it meant that Real_Time might not
be monotonic).

If you never let the OS change its time sync, Calendar would do just
fine.