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From: "Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>
Newsgroups: comp.lang.ada
Subject: Re: Ada.Calendar and NTP (and Unix Epoch)
Date: Wed, 25 Jul 2012 08:32:05 +0200
Organization: cbb software GmbH
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Date: 2012-07-25T08:32:05+02:00
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On Wed, 25 Jul 2012 01:22:55 +0400, Vasiliy Molostov wrote:

> Dmitry A. Kazakov <mailbox@dmitry-kazakov.de> �����(�) � ����� ������ Wed,  
> 25 Jul 2012 00:29:00 +0400:
> 
>> On Tue, 24 Jul 2012 23:43:49 +0400, Vasiliy Molostov wrote:
>>
>>> Converting from some representation into authoritative monotonic time is
>>> "mission impossibe", since important data may be lost, because this
>>> important data belongs entirely to the representation, and can not be
>>> expressed in monotonic authoritative source.
>>
>> Possible, but under two conditions:
>>
>> 1. the corresponding time sources are synchronized;
> 
> If you can synchronize representations, you are a god of time  
> representations.

Synchronization does not necessarily means that you control the clocks. 

However it is true that the effect of clock synchronization is by
definition local. In particular it implies that more distant time stamps
are less sense any conversion would make. In short, some real-time clock
readings can be converted if synchronized. Anything else is most likely
garbage.

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