Python implementation of time functions certainly has nothing to do with UT1, which is the time as measured by (modern) sun dials.  The correct name would be POSIX time.  As explained in POSIX rationale,

"""
Coordinated Universal Time (UTC) includes leap seconds. However, in POSIX time (seconds since the Epoch), leap seconds are ignored (not applied) to provide an easy and compatible method of computing time differences. Broken-down POSIX time is therefore not necessarily UTC, despite its appearance.
""" -- http://www.opengroup.org/onlinepubs/9699919799/xrat/V4_xbd_chap04.html

Nevertheless, UTC time is used throughout the standard.  For example,

"""
The gmtime() function shall convert the time in seconds since the Epoch pointed to by timer into a broken-down time, expressed as Coordinated Universal Time (UTC).
""" -- http://www.opengroup.org/onlinepubs/9699919799/functions/gmtime.html


I don't think there is much that can be improved in the Python documentation other than to stop referring to UTC as if it was a geographical location.