On 2021-05-23 16:33, Clive D.W. Feather wrote:
Brian Inglis via tz said:
From the legal viewpoint in the English common law based legal world, which is most of the Commonwealth of Nations and former colonies including the USA, mean solar time represented by UT and some offset(s) still applies, due to pre-atomic precedents, regardless of IAU, ISO, or ITU opinions about ephemerides, atomic physics, or radio signals. If tested, I would expect the current definition of the second may have no legal basis in those jurisdictions, and it would be interesting to see if a case could be made on the technicality that times commonly used and often relied upon may not be legally valid.
I can't speak for anywhere else, but if it became a significant point in a case, I would expect an English judge to rule that "Greenwich mean time" has now come to mean UTC.
I think rather that UTC (as it is currently defined) could be ruled a legally valid approximation to mean solar time at the standard meridian, which is what the precedents deal with. -- Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada This email may be disturbing to some readers as it contains too much technical detail. Reader discretion is advised. [Data in binary units and prefixes, physical quantities in SI.]