> UTC is my *favourite* acronym. It stands for Universal Coordinated > Time, but the astute will notice that the letters are in the wrong > order.
Get used to the fact that not everything is American. The acronyms are French. The BIPM happens to be located in France. That's the internationally authoritative organisation for standards and measures (and e.g. the keeper of the physical metre and kilogram). The BIPM may well have started before the Americans were even on the scientific radar. THere's truckloads of info at http://www.bipm.fr/ > I thought the main difference between UTC and GMT was that GMT did not > have leap-seconds. No. GMT is simply UTC in time zone 0. UTC does not consider time zones ever. The difference between UTC and TAI is a whole number of seconds, currently 32. > Would that make GPS-time the same as GMT? When GPS started, yes. Not now. Again when sufficient number of leap seconds have been removed (could be some wait, as it depends on how the earth goes round). To be precise, some dumbo (excuse me) had this "smart" idea to start GPS off on UTC, but then not wanting to deal with leap seconds. Therefore, GPS has a permanent offset of 13s to TAI. I haven't found any proof that the internet is supposed to run on UTC (anyone got a source?), but as servers and workstations already handle time zones, which don't exist in TAI, and countries run their official time on UTC (dunno whether there are exceptions, not Europe and NZ), it would be the only sensible thing to do. Those running stratum 1 NTP servers are therefore required to feed the leap seconds info into their computers when it becomes available, so that the difference to GPS-time can be calculated. Of course, *really* smart would have been to feed the UTC-TAI difference through GPS... Perhaps there'll be some Galileo receivers one day which can do that, if the Europeans ever manage to tell the Yank-bullies to get stuffed (and their own shite sorted). Volker -- Volker Kuhlmann is possibly list0570 with the domain in header http://volker.dnsalias.net/ Please do not CC list postings to me.
