The solution is simple - move to TAI. That is the _true_ time, what the master clocks actually keep. UTC is just a variant for creatures living on the surface of the Earth. On Fri, Jan 20, 2012 at 9:20 AM, Phillip Hallam-Baker <hallam@xxxxxxxxx> wrote: > If we are ever going to get a handle on Internet time we need to get rid of > the arbitrary correction factors introduced by leap seconds. > > The problems caused by leap seconds are that they make it impossible for two > machines to know if they are referring to the same point in future time and > quite often introduce errors in the present. > > 1) No machine can determine the number of seconds between two arbitrary UTC > dates in the future since there may be a leap second announced. Not true for TAI. > > 2) If Machine A is attempting to synchronize with machine B on a future > point in time, they cannot do so unless they know that they have the same > view of leap seconds. If a leap second is announced and only one makes the > correction, an error is introduced. Not true for TAI > > 3) In practice computer systems rarely apply leap seconds at the correct > time in any case. There is thus a jitter introduced around the introduction > of leap seconds as different machines get an NTP fix at different points in > time. Not an issue for TAI > > 4) Even though it is possible to represent leap seconds correctly in > standard formats, doing so is almost certain to exercise code paths that > should be avoided. > Not an issue for TAI Note, also, that the ITU proposal is not to _remove_ leap seconds, but to stop _issuing_ them (i.e., it could be rescinded fairly easily if in say 20 years someone agitated strongly to bring leap seconds back). > > Since the ITU does not look like sorting this out, I suggest we do so in the > IETF. There is no functional reason that Internet protocols should need leap > seconds. > > I suggest that the IETF plan to move to Internet Time in 2015, immediately > after the next ITU meeting. Internet time would be TAI plus the number of > leap seconds that have accumulated up to the next ITU decision point. So if > UTC drops leap seconds at the next meeting the two series will be in sync, > otherwise there will be a divergence. Makes no sense to me. Please don't continue to create more time scales that are "TAI plus some arbitrary constant." I believe that would make at least 4 separate ones (ET/TDT/TT, UTC, GPS internal time, plus this), which would be IMO at least 4 too many. If there is to be an internet time, it should simply be TAI. Then, the conversion to UTC is just an addition, and there would be no reason to have the messy interpolation during a leap second. just to change the addend. Regards Marshall > > > > -- > Website: http://hallambaker.com/ > > > _______________________________________________ > Ietf mailing list > Ietf@xxxxxxxx > https://www.ietf.org/mailman/listinfo/ietf > _______________________________________________ Ietf mailing list Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf