On Mon 2019-12-16T14:10:21+0000 Clive D.W. Feather hath writ:
You take a Gregorian calendar (by default; in principle you could use Julian or something else) and use it to count *all* SI seconds, so that every day has exactly 86400 seconds in it. It works the same way as UT1, but without the unpredictable-length "seconds".
In 1968 between a pair of meetings the atomic clock and CCIR folks ascertained that they could not use that scheme in broadcast time signals, and that is when and why the notion of the leap second came into being. -- 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