On Wed, May 31, 2017 at 6:37 PM, Chris Barker <chris.barker@noaa.gov> wrote:
Couldn't the work be done in parallel?

At this point this seems to be wasteful. More work for reviewers and potentially more work for Mathieu if we decide to change the behavior before applying the patch.
 
if Mathieu wants to write a C version, it could be dropped in to datetime at any point.

Right, and this is the reason to focus on the pure Python version first.