On Tue 2023-05-02T18:43:37+0200 Benjamin Drung hath writ:
The wording above will get more complicated by mid 21st century as UTC deviates notably from GMT.
For the tz project UTC = GMT, isn't it? Can you suggest a better wording?
Alas no. The folks pushing to abandon the leap second have admitted that some kind of adjustment of "new UTC" will eventually be needed lest it deviate too far from GMT. That remains unexplored. It will want worldwide consensus of governments and data models on a meaning of time and calendar days which is satisfactory for political and technical purposes. If a government objects to a deviation of 15 seconds that agreement could be needed by 2050, but a larger tolerance should be acceptable and that should push the need to the end of this century. The current wording is sloppy because UT (and UT1) have always been deviating from GMT, just not by enough for people to notice. The better wording cannot happen until there is a vocabulary for what we want time to mean and to tell us. -- 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