[LEAPSECS] Time math libraries, UTC to TAI

[Brooks Harris]

On 2016-12-30 12:39 PM, Steve Allen wrote:
> On Fri 2016-12-30T11:37:38 -0500, Brooks Harris hath writ:
>> There is a hole in the data of these tables; Rec 460 tells us the
>> origin of TAI is "1 January 1958" but the first TAI-UTC value listed
>> in the tables is in 1961 - what happened between 1958 and 1961? What
>> does "1 January 1958" mean; 1958-01-01 00:00:00 (TAI) or 1958-01-01
>> 00:00:00 (UTC)? Wait, did UTC exist in 1958? Why 1958?
> This is like learning that the Dow Jones Industrial Average is
> calculated from the weighted trade prices of 30 companies and then
> asking "Can I use the prices of those 30 companies to calculate what
> the DJIA was in 1950?"
>
> All of the companies that have been part of the DJIA, and all of the
> weights that have been used, are documented, but the many sites that
> publish the DJIA never talk about them.
Right. I forgot to also mention it would be very helpful if the UTC 
specs were collected into a single authoritative reference because a lot 
of implementers get confused and discussions go sideways, even here at 
LEAPSECS.

-Brooks


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