On Thu, May 17, 2018 at 7:12 PM Wes Turner <wes.turner@gmail.com> wrote:
AstroPy solves for leap seconds [1][2] according to the IAU ERFA (SOFA) library [3] and the IERS-B and IERS-A tables [4]. IERS-B tables ship with AstroPy. The latest IERS-A tables ("from 1973 though one year into the future") auto-download on first use [5].

I've just tried it.  Unfortunately, it does not seem to be compatible with PEP 495 datetime yet:

>>> t = astropy.time.Time('2016-12-31T23:59:60')
>>> t.to_datetime()
Traceback (most recent call last):
 ...
ValueError: Time (array(2016, dtype=int32), array(12, dtype=int32), array(31, dtype=int32), array(23, dtype=int32), array(59, dtype=int32), array(60, dtype=int32), array(0, dtype=int32)) is within a leap second but datetime does not support leap seconds 

Maybe someone can propose a feature for astropy to return datetime(2016,12,31,23,59,59,fold=1) in this case.
 

[1] http://docs.astropy.org/en/stable/time/#time-scales-for-time-deltas
[2] http://docs.astropy.org/en/stable/time/#writing-a-custom-format
[3] "Leap second day utc2tai interpolation"
https://github.com/astropy/astropy/issues/5369
[4] https://github.com/astropy/astropy/pull/4436
[5] http://docs.astropy.org/en/stable/utils/iers.html