[LEAPSECS] Common Calendar Time (CCT) -Brooks Harris

[Ian Batten]

On 18 Jan 2014, at 01:22, Zefram <zefram at fysh.org> 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