It occurs to me that my proposal for a rational replacement for daylight saving time also provides an answer to the leap second question.
http://catless.ncl.ac.uk/Risks/25.10.html#subj1 The essence of sunrise time is that we reset our clocks each day to a fixed time when the sun rises at a benchmark location. For the UK, the benchmark location would be where the Greenwich meridian crosses the Tropic of Cancer. The fixed time is 06:44, which is the time of the latest sunrise at that location according to mean solar time (UT1). The reset is accomplished by adjusting your timezone offset, which you'd do a few hours earlier than sunrise to avoid disrupting early risers, and you'd round the offset to the nearest minute to avoid breaking things like ISO 8601. If you are setting civil time according to these rules, then civil time is by definition coupled to the rotation of the Earth, and there can be no accelerating secular difference between the two. This is true whatever time scale you use as the basis from which timezone offsets are calculated. You have a pretty free choice of basis timescale long as its length of day is not too far from the Earth's LOD. The resulting system has several useful properties: * You can use atomic time as your basis timescale, with a LOD of 86400 SI seconds. * The only other time(s) you need to worry about are local time(s), just like the current situation. * Both basis time and local time have fixed-length minutes and hours, which is much simpler than the current situation. * Basis time has fixed-length days, which is also a simplification. * Local time has variable-length days, just like the current situation. * Small timezone adjustments are less disruptive than large ones. * Frequent timezone adjustments make timezone-related bugs more obvious and therefore easier to fix. * It preserves the role of Earth location scientists in time keeping. Tony. -- f.anthony.n.finch <d...@dotat.at> http://dotat.at/ SOUTH UTSIRE: SOUTHERLY 3 OR 4 VEERING NORTHWESTERLY 5 TO 7. MODERATE. DRIZZLE THEN FAIR. MODERATE BECOMING GOOD. _______________________________________________ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs