This is the module docstring:
"""Concrete date/time and related types -- prototype implemented in Python.

See http://www.zope.org/Members/fdrake/DateTimeWiki/FrontPage

See also http://dir.yahoo.com/Reference/calendars/

For a primer on DST, including many current DST rules, see
http://webexhibits.org/daylightsaving/

For more about DST than you ever wanted to know, see
ftp://elsie.nci.nih.gov/pub/

Sources for time zone and DST data: http://www.twinsun.com/tz/tz-link.htm

This was originally copied from the sandbox of the CPython CVS repository.
Thanks to Tim Peters for suggesting using it.
"""

The first link is broken, the following two links look like more or less random page that can be found by googling, the .gov site might have been useful but it's broken, and the last link looks OK.
I think it would be better to replace the whole docstring with something more descriptive.  I'm not sure those links should be kept at all.