Re: [Cbor] draft-bormann-cbor-time-tag: POSIX and UTC are not the same
Emile Cormier <emile.cormier.jr@gmail.com> Sat, 03 April 2021 19:16 UTC
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From: Emile Cormier <emile.cormier.jr@gmail.com>
Date: Sat, 03 Apr 2021 16:16:13 -0300
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To: Carsten Bormann <cabo@tzi.org>
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Subject: Re: [Cbor] draft-bormann-cbor-time-tag: POSIX and UTC are not the same
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On Sat, Apr 3, 2021 at 4:34 AM Carsten Bormann <cabo@tzi.org> wrote: > > TAI, GPS are true monotonic time scales. Leap seconds have no influence > on them (what cppreference calls “including leap seconds”). > As C++ utc_clock "includes leap seconds”, it appears to be a TAI > referenced time scale (with a constant offset of 10 seconds from TAI). > > Ah yes, the C++ utc_clock having a constant offset from TAI makes sense to me now. This was the piece of the puzzle that my brain was missing. :-) The C++ tai_clock ticks do indeed have a constant 10 second offset from utc_clock ticks (ignoring epoch starting moments) as shown here: https://github.com/HowardHinnant/date/blob/77bd6b92a4f7f6a1bbbc44952e6502a3448376b0/include/date/tz.h#L2084 Note that HowardHinnant/date was the incubator project that lead to the enhanced date/time facilities in C++20. Thank you bearing with me as I grappled to understand this.
- [Cbor] draft-bormann-cbor-time-tag: POSIX and UTC… Emile Cormier
- Re: [Cbor] draft-bormann-cbor-time-tag: POSIX and… Carsten Bormann
- Re: [Cbor] draft-bormann-cbor-time-tag: POSIX and… Henk Birkholz
- Re: [Cbor] draft-bormann-cbor-time-tag: POSIX and… Emile Cormier