On 18 Jan 2014, at 01:22, Zefram <[email protected]> wrote: > Brooks Harris wrote: >> Yes, I understand that. Perhaps using the word "origin" was careless. >> Maybe you can suggest a better term. > > "proleptic". You may usefully add "with astronomical year numbering" to > make clear that zero and negative year numbers are valid. But really, > when you're defining a time scale, the calendar is irrelevant. It's a > separate concern that should be addressed separately. > >> Of course the idea is that dates after 1972-01-01T00:00:00Z are >> "earth corrected" (Leap Seconds). > > Are you implying that dates before are not? That wouldn't be a proleptic > UTC.
Can someone suggest an application for a proleptic UTC representing dates in the distant past such that the differences between it and, say, proleptic UT1, proleptic TAI or proleptic GPS time would be significant, and where the issues would be common to some other application? Outside the production of historical astronomical data, where I suspect they are going to want a timescale which reflects variations in day length anyway, it's hard to think of applications where the recorded timestamps have precision better than the differences between these various putative timescales. ian _______________________________________________ LEAPSECS mailing list [email protected] http://six.pairlist.net/mailman/listinfo/leapsecs
