On Mon, Apr 6, 2015 at 4:58 PM, <random832@fastmail.us> wrote:
In my opinion all codes accepted by C11 *should* be supported by python;
its present failure to do so is a wart. Any new work to address this
issue should be in the form of a pure python strftime function rather
than an effort to document every platform's idiosyncracies.

An issue [1] to implement that was open almost 7 years ago and seen little progress since then.  The problem is that there is no reliable cross-platform method to access locale information that stftime needs.  One could try to do something with nl_langinfo(), but that is a pre-Unicode interface that assumes one global locale, so modern platforms have extended it in various incompatible ways. Note that strftime itself assumes one global locale and that's another reason to switch to something more modern.

[1] http://bugs.python.org/issue3173