Time Library Organisation

Aaron Denney wnoise at ofb.net
Fri Jan 28 16:26:26 EST 2005

On 2005-01-27, Marcin 'Qrczak' Kowalczyk <qrczak at knm.org.pl> wrote:
> Aaron Denney <wnoise at ofb.net> writes:
>>>>> DJB (the author of libtai) disagrees with POSIX about what
>>>>> gettimeofday should return, and assumes that it actually returns
>>>>> what he wishes it returned.
>> More accurately, he expects admins to set it to TAI, and not run
>> programs that set it to other than non-TAI.
> Does he propose a way for programs to discover whether the system
> clock is TAI or UTC?

No, he doesn't.

> Does he provide an NTP client which works when it's TAI?


Yes, other programs will then have offset time values, etc.

> I wonder why DJB and other people didn't propose such a solution,
> and instead they complain how POSIX is broken and propose something
> which breaks programs which obey POSIX rules.

Because POSIX rules are counterintuitive, and usually not correctly
implemented.  There's a somewhat reasonable folk-belief that the
committee just didn't know quite enough about time and expected UTC to
have behaviour more like TAI.  Getting rid of what they see as
intolerably broken behaviour is more important than interoperability.

(I agree with most of the rest of what you said.)

Aaron Denney

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