jquery/jquery-ui — pull request #1054 by ptlis (2013-08-11 19:34:41+00:00)
Title: Datepicker: Added data-day attribute to 'day' cells of widget.

I couldn't find a sensible way to automate selection of an arbitrary day in my functional tests (using Selenium2) and the addition of a data-day attribute alongside the data-month & data-year attributes solves this problem.