The date control to change the Date Taken is cumbersome.
The Date Control for changing the date only allows you to navigate to a date. You should also be able to just type the date.
Likewise, when it opens, it opens to the current date. If you need to adjust the date of a photo by only a day but the photo is old, you must step backwards month by month.
Wolfgang Jeschke commented
In addition to this also the time should be editable, not only the date - sequences of pictures taken with different cameras having different internal times is otherwise practically impossible.