TAI zone?

Bradley White bww at acm.org
Thu Jun 30 18:02:31 UTC 2011


On Thu, Jun 30, 2011 at 7:24 AM, David Magda <dmagda at ee.ryerson.ca> wrote:
> Unix-y systems keep time in POSIX "time scale" (?), and NTP uses UTC.
>
> Given that TAI is neither of these, if one would like to use a time
> scale that does not experience leap seconds, one need a way of telling
> the various time routines to translate the internal POSIX/UTC counters
> to a different "local" time.
>
> As I type this, my TZ=America/Toronto, and so the time is roughly:
>
>        Thu Jun 30 07:20:50 EDT 2011
>        Thu Jun 30 11:20:50 UTC 2011
>
> but if I set TZ=TAI, it would convert my NTP synced computer clock up
> by 34s:
>
>        Thu Jun 30 11:21:24 TAI 2011
>
> So yes, TAI is "just a count of seconds from its offset", but how
> does one tell a utility like date(1) to add those seconds? Hence my
> original question: if all these people who can't / don't want to deal
> with leap seconds want something that ignores it, what option would
> they have? Would a TZ=TAI be possible?

Use the "right" files, and judiciously place a call to the ado
localtime.c:time2posix() in your NTP server.  Then all is well.

[You may need a time2posix() in other places that assume 60-second
minutes, but when I did just that circa 1990 there were but a few.]



More information about the tz mailing list