[LEAPSECS] leap minute or hour

[Eric Scace]

   If a leap minute were to be added/removed at some future date when UTC became significantly more that 30 seconds different from mean solar time, many years could be made available (e.g., 20 years!) to retire/replace/rewrite software for such an unusual event whose occurrence is on a KNOWN date/time in the future.

   This is much easier to deal with than writing code for future leap second changes on dates yet to be established/promulgated.

   As an example, if the delta was wandering around 40 seconds, BIPM could announce a leap minute to occur twenty years from the date of the announcement… and, if a sense of humor existed, put it on Feb 29th of a leap year.