You can see cell d2 shows the correct date.
Now right click on cell d2 and select format cells. Select Custom on popup box.

There is a combo box named type. Enter bellow mentioned formats one at once into that box.
- d
- dd
- ddd
- m
- mm
- mmm
- mmmm
- yy
- yyy
- dd,ddd
- yy-mmm-dd,ddd
See changes on the date and practice.