This might be Apple UIDatePicker issue as well.
While the picker is animating, if user tap on "Select", UI seems wait for a while to let datePicker settle down to the final value, but the return value will still show the original value.
Tried capturing value through UIControlEventValueChanged, seems it able to return the final value even if DateSelectionViewController is dismissed.
I'm not sure how it could be patched in the component itself since UIDatePicker doesn't expose much info about the UI. Maybe you have some better idea.