Stretch the top line of the "Task Bar" upwards a bit, the date and day of week will appear.
But if you don't want to stretch the Task Bar, I would download a freeware called TClock 2.2.8 at http://homepage1.nifty.com/kazubon/tclock/. Read the readme.txt file for instructions. If everything OK, now you will see the date will displayed in Day, Date, Time in one line. Right-click in that date area for more adjustment options.
I know i saw this reg tweak somewhere, right now i have the taskbar on the left side and about an inch wide! just so that it can show the full date and time, how can i get this display when the taskbar is on the bottom.? i just lose track of days....