(stable) Set time and date on Calendar Date Control form

Summary: Recurring events will fatal a Calendar with this not set. newDateTime requires a date and time to be called property. I think this is correct fix? Fixes T10766

Test Plan: Build a recurring event, pull up /calendar/, see recurring events as expected. Previously, fatal.

Reviewers: lpriestley, epriestley

Reviewed By: epriestley

Subscribers: CodeMouse92, Korvin

Maniphest Tasks: T10766

Differential Revision: https://secure.phabricator.com/D15666