Otherwise, py8601 (https://bitbucket.org/micktwomey/pyiso8601/) looks pretty popular and well maintained (various committers, started in 2012, last commit in 2016).  I don't think that we should add the iso8601 module to the stdlib, but merge iso8601 "features" into the datetime module.  The iso8601 module supports Python 2.7 and so has to implement its own timezone classes. The datetime module now has datetime.timezone since Python 3.2 for fixed timezone. To me it's the finest, the most elegant, and no other one can claim to be more robust since it's probably the #1 iso parsing functions used in python. Have a look at https://docs.djangoproject.com/en/1.9/_modules/django/utils/dateparse/#parse_datetime.