[LEAPSECS] the big artillery

Gerard Ashton ashtongj at comcast.net
Tue Nov 4 11:53:27 EST 2014


Of course Brooks Harris is free to define proleptic UTC any way he pleases
within the confines of a document he has control over, including a post to
this mailing list. But I think the term "proleptic UTC", outside the
confines of a document that gives it a proprietary definition, could mean a
variety of things. For example, the Standards of Fundamental Astronomy
subroutine  iauDat provides the delta between TAI and UTC, and the source
code comments say "UTC began at 1960 January 1.0 (JD 2436934.5) and it is
improper to call the function with an earlier date." In as much as UTC
attempted to track UT2 in the 1960s, I would regard 1960 January 1.0 as the
dividing point between proleptic UTC and UTC, and I would regard proleptic
UTC as synonymous with UT2. If it turns out that creates a discontinuity at
the dividing point, so be it.



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