Automattic/custom-metadata — pull request #113 by tmtrademark (2014-07-25 18:55:01+00:00)
Title: Changing order of operations in _sanitize_field_value

Locally, I made the datepicker field cloneable, but _sanitize_field_value chokes when strtotime() is fed an Array of values. Switching the order of sanitize_callback allows for customized sanitization of these values.