M. Warner Losh wrote:
GPS is also used for UTC today. Many ntpd's are stratum 1 tied to a GPS receiver.
I imagine two parallel time infrastructures, one synchronised to TAI, the other to "rubber" mean universal time. Stratum 0 devices for the latter would probably have to use radio. So, sure, there's an infrastructure cost for a sensible time of day... > ntpd is UTC, by definition. I wonder how easily NTP could be generalised to transmit different timescales without too much confusion? Using different UDP port numbers might be one option. -- Ashley Yakeley