==================
- Remove support for guessing the timezone name when a timestamp
exceeds the value supported by Python's ``localtime`` function. On
platforms with a 32-bit ``time_t``, this would involve parsed values
that do not specify a timezone and are past the year 2038. Now the
underlying exception will be propagated. Previously an undocumented
heuristic was used. This is not expected to be a common issue;
Windows, as one example, always uses a 64-bit ``time_t``, even on
32-bit platforms. See
https://github.com/zopefoundation/zope.datetime/issues/4
- Use true division on Python 2 to match Python 3, in case certain
parameters turn out to be integers instead of floating point values.
This is not expected to be user-visible, but it can arise in
artificial tests of internal functions.
- Add support for Python 3.5 and 3.6.
- Drop support for Python 2.6, 3.2 and 3.3.