On Wed 2020-01-15T11:28:35+0000 Michael H Deckers hath writ:
Isn't that obvious? If UTC cannot deviate from UT1 by more than 0.7 s (as Recommendation 460 originally stipulated) then UTC cannot have leaps by more than 1.4 s. Leaps by N s are only possible when |UTC - UT1| is allowed to be >= N/2 s.
The draft version of Study Group VII (the one that allows for leaps in UTC by an integral number of seconds) specifies no bound for |UTC - UT1|.
The original version of CCIR Rec. 460 did not specify any bound. See volume 3 page 227 http://search.itu.int/history/HistoryDigitalCollectionDocLibrary/4.278.43.en... The draft with "integral multiples" was pushed through in a rush in 1970 January because of an imminent political deadline from Germany and other political pressure from USSR. The technical details with max 0.7 second deviation came from Report 517 which was not forged until 1971 February and included into the CCIR volume 3 as addendum starting on page 258a. That 0.7 limit was disregarded in less than two years also due to Soviet political pressure, leading to a rewrite that gave the limit of 0.8 second even. though the 0.7 limit had already been hard-coded into the format of the broadcast time signals. -- 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