The 3.x datetime documentation contains the following footnote:

> In other words, date1 < date2 if and only if date1.toordinal() < date2.toordinal(). In order to stop comparison from falling back to the default scheme of comparing object addresses, date comparison normally raises TypeError if the other comparand isn’t also a date object. However, NotImplemented is returned instead if the other comparand has a timetuple() attribute. This hook gives other kinds of date objects a chance at implementing mixed-type comparison. If not, when a date object is compared to an object of a different type, TypeError is raised unless the comparison is == or !=. The latter cases return False or True, respectively.

But in 3.x, comparison no longer falls back to comparing object addresses.  Also, some of the comments on issue 8005 seem to suggest that this footnote is not actually true in 3.x (aside from the first sentence, of course).  But regardless, the footnote should not refer to a long dead interpreter behavior as if it were still around.

> But in 3.x, comparison no longer falls back to comparing object addresses.

What is the default fallback in 3.x?

There is none.  It raises a TypeError.  See https://docs.python.org/3/reference/expressions.html#value-comparisons

New changeset 9c223794c754408644c16349b85dd27fdba8a926 by Miss Islington (bot) (Danish Prakash) in branch 'master':
bpo-34365: Update date object documentation (GH-8814)
https://github.com/python/cpython/commit/9c223794c754408644c16349b85dd27fdba8a926

Thanks!

New changeset e2b40f4ce954ea3d35a73541029b2253abd9d245 by Miss Islington (bot) in branch '3.7':
bpo-34365: Update date object documentation (GH-8814)
https://github.com/python/cpython/commit/e2b40f4ce954ea3d35a73541029b2253abd9d245

New changeset 8a2c2d4e1b6b46a9a982e5c064ca4399ec28d55d by Miss Islington (bot) in branch '3.6':
bpo-34365: Update date object documentation (GH-8814)
https://github.com/python/cpython/commit/8a2c2d4e1b6b46a9a982e5c064ca4399ec28d55d