On 2017-04-10, at 10:15, Ward, Mike S wrote:
>
> ... If you want to have truly accurate results, including all the leap
> seconds baggage (Hi Gil), ...
>
And that depends on your notion of "truly accurate".
If you want physical time, *ignore* CVTLSO.
If you want IT-style time, subtract CVTLSO.
If you want Terrestrial Time, study websits at USNO, NIST, RGO, IERS, etc.
https://en.wikipedia.org/wiki/%CE%94T
(CVTLSO is based on 1972. The difference between TAI and TT may have been
different (smaller?) in 1970.)
(You probably don't care about a minute, perhaps not even an hour or a day.)
-- gil
