I suspect that you two will continue in your naif views, but let me try one more time, taking first Mr Gilmartin and then Dr Merrill.
The basic sequence, reference standard, is TAI. UTC is a derived quantity. The alignment of civil dates with the seasons is a desideratum. Precession very gradually brings UTC (and other lunisolar calendars too) out of alignment with the seasons on earth. Leap seconds correct for this precession, keeping UTC seasonally aligned, or nearly so. (There are arguments against this. The Islamic lunar calendar rotates the privations of Ramadan/Ramazam through the seasons; a traditional English Christmas dinner eaten in Australian high summer is problematic; etc., etc. It is, however, the prevailing view.) Sequences like 23h 59m 59s 23h 59m 60s 00h 00m 00s are [simplistic] expository devices directed at the uninformed. They correspond to physical reality in the same way that the hydrodynamic-analogy diagrams of water flowing through pipes used to explicate electric-current flow in introductory physics texts correspond to what goes on in an electric circuit. The arithmetic of multiple moduli and several simultaneous cycles used to convert counter values into calendar dates always numbers seconds in the sequence 0, 1, 2, . . . , 59 It knows nothing of and cannot create a time value of the form xx xx 60. 'Splain' is presumably subliterate folksy for 'Explain', but there does not seem to me to be anything to much to explain. Take thought, Dr Merrill. As perhaps helpful in your ruminations consider a local time L and a GMT offset o. Does the pair (L,0) represent a standard time, EST say? Or again, does it represent a daylight-savings/summer/official time, EDT say? How, in principle, does one distinguish them? John Gilmore, Ashland, MA 01721 - USA ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
