Re: [LEAPSECS] Introduction of long term scheduling

From: Michael Deckers <Michael.Deckers_at_fujitsu-siemens.com>
Date: Thu, 04 Jan 2007 10:28:40 +0000

   On 2007-01-03, Poul-Henning Kamp commented on Bulletin D 94:

> That's an interesting piece of data in our endless discussions about
> how important DUT1 really is...

   So it appears that DUT1, an approximation of UT1 - UTC, is not of much use,
   even though it is disseminated with many time signals. On the other hand,
   POSIX implementors need the values of DTAI = TAI - UTC, the count of leap
   seconds, at least for those UTC timestamps in the future as may occur
   during the operation of the system.

   This leads me to my question: would it be helpful for POSIX implementors
   if each and every UTC timestamp came with the corresponding value of DTAI
   attached (instead of DUT1)? Would this even obviate the need for a leap
   seconds table?

   I realise that this would require changes or extensions to the time
   interfaces of POSIX (eg, a "time_t" value alone could no longer encode a
   complete timestamp). My question is just whether such timestamps,
   indicating both UTC as time-of-day and TAI as "interval time", could
   be a viable alternative to the frequent updates of leap second tables.

   Michael Deckers
Received on Thu Jan 04 2007 - 02:29:22 PST