Background
Given a content type with a date field defined (field_date) and a custom input format defined of some value (e.g. 'm d, Y'), save that to the database. Create some content for demonstration. Then, change the input format to a non-custom one in the select list and save that to the database.
Expected Behavior
When creating a new piece of that content, the date field should ask for an hour and minute (and second, if configured), using the non-custom format last saved to the database.
Actual Behavior
When creating a new piece of that content, the date field only asks for the month, day, and year, in the custom format first specified.