In message: <[EMAIL PROTECTED]> Neal McBurnett <[EMAIL PROTECTED]> writes: : On Mon, Feb 06, 2006 at 10:37:37AM -0700, Rob Seaman wrote: : > 1) TAI can be recovered from UTC given a table of DTAI. : > 2) NTP can convey TAI as simply as UTC. : > 3) Deploy a small network of NTP servers to keep TAI, not UTC. : > 4) NTP client machines could therefore trivially select between TAI and : > UTC by subscribing to different servers. : > 5) This would provide an unbiased experimental sandbox for civil : > timekeeping issues. : : Since TAI can be recovered from UTC, and hosts that use NTP know UTC, : those hosts can serve any time they want to clients on that host. I : see little reason to change the particular timestamps that are used in : the NTP protocol, an less reason to have two different timestamps : within NTP, or to require users on ntp-using hosts to switch their : ntp servers just to get a different timescale.
ntp time stampes are ambiguous at leap seconds (the leap indicator bits aren't part of the time stamp, exactly), which is a good reason to change them. However, the cost to change them could be quite high if done in an incompatible manner. : That's why I support the "Fixing POSIX time" proposal from : Poul-Henning Kamp. This can be implemented with the latest NTP : daemons. The operating systems would seem to just need the right sort : of CLOCK_NTP definition for /usr/include/linux/time.h or equivalent, : and the appropriate conversion routines as he outlined. Agreed. : I'd like to see a standard for NTP that includes the TAI information : that is now passed in non-standard formats, but that is a separable : issue. I believe that the new draft standard of ntp uses TAI time for its time exchange, and explicitly includes DTAI information in a standard format. Since the protocol version changes, there's no ambiguity and that's a good time to change things like this. However, I've not read the latest ntpng drafts to confirm this. Warner