Convert date control dropdowns to an input for date
Summary: Ref T8060, Convert date control dropdowns to an input for date
Test Plan: Create new Calendar event, use US time format to enter a date or use datepicker, confirm dates are interpreted correctly.
Reviewers: #blessed_reviewers, epriestley
Reviewed By: #blessed_reviewers, epriestley
Subscribers: Korvin, epriestley
Maniphest Tasks: T8060
Differential Revision: https://secure.phabricator.com/D13010