DatePicker should let developer decide if the chosen day of the month should be persisted from month-to-month.

By default the DatePicker remembers the day of the month the user has selected, and that day gets styled differently even when the user navigates away to a different month: the user selects January 12th and then navigates to August, and the 12th day of August is styled differently too.

But there are many use cases for a DatePicker where it is not appropriate behavior to remember the previously selected day of the month when the user navigates to a different month. Remembering the day can actually make things confusing for the user in applications where this behavior is not the right behavior.