On 2023-11-18 1:52 PM, Steve Allen via tz wrote:
On Sat 2023-11-18T12:39:42-0500 Brooks Harris via tz hath writ:
I hope we do not overlook the fact that the term "standard" is ambiguous. The legal situation in the US is less clearly defined than that.
PUBLIC LAW 89-387-APR. 13, 1966, AN ACT SEC. 3. (a) During the period commencing at 2 o'clock antemeridian 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. Ah yes.
I am careful to think of local time as offsets from UTC in the time domain. Its exact relation to longitude and solar time has become vague.
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. Or solar time.
Widespread agreement with high precision of the answer to "What time is it?" is imperative, but common language and legal language are imprecise and misleading. I think of it as "the fog of timekeeping".
-Brooks
-- Steve Allen <sla@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB 260 Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 https://www.ucolick.org/~sla/ Hgt +250 m