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Re: [Cbor] draft-ietf-cbor-date-tag-02 - handling of time zone offsets

Michael Richardson <mcr+ietf@sandelman.ca> Wed, 01 July 2020 15:51 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
To: Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de>
cc: Carsten Bormann <cabo@tzi.org>, draft-ietf-cbor-date-tag@ietf.org, cbor@ietf.org
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Date: Wed, 01 Jul 2020 11:51:13 -0400
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Subject: Re: [Cbor] draft-ietf-cbor-date-tag-02 - handling of time zone offsets
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Juergen Schoenwaelder <j.schoenwaelder@jacobs-university.de> wrote:
    > I am not sure about Angela's passport but my passport in addition
    > states where I was born (which implies a certain time zone). I do not
    > know whether this example is useful or not, perhaps you just want to
    > say that in some use cases the time zone does not matter and this is
    > fine.

    > But on the other hand, two systems may tag an event with 1954-07-17
    > but in UTC they would be not the same dates or two systems can tag an
    > event with two different dates but they are actually the same date in
    > UTC. In distributed systems operating across many timezones, simple
    > comparisons of date values can be surprising.

The failure of the Nipponese to declare war on the USA on December 8, 1941
(they date of the attack on Pearl Habou^Hr in Japan...) is perhaps a better
example of failures to get the time zone right.

--
Michael Richardson <mcr+IETF@sandelman.ca>, Sandelman Software Works
 -= IPv6 IoT consulting =-

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