On 2023-11-18 18:52, Steve Allen via tz wrote:
That same "antemeridian" language persists in the 2005 revision of US law. That language made sense in 1966 because time was based on meridians, but even then the meridian for measuring UT[012] was known not to be the Greenwich meridian. In the 2005 revision the basis of UTC was not really even the meridian of UT1. If the ITU WRC this week agrees with the CGPM about the future of UTC then time will no longer be related to any meridian.
Lest the wrong impression of US legislation pertains: the _currrent_ version of 15 U.S.C. 261 of 2007 reads in part: " standard time of the first zone shall be Coordinated Universal Time retarded by 4 hours; ..." so the term "standard time" is defined as it used by tzdb, and no "antemeridian" is referenced. Current law references UTC: " the term ‘Coordinated Universal Time’ means the time scale maintained through the General Conference of Weights and Measures and interpreted or modified for the United States by the Secretary of Commerce in coordination with the Secretary of the Navy. " See eg [https://www.nsf.gov/nsb/meetings/2017/0221/presentations/20170221-EE-Open-AI...] Michael Deckers.