I thought it was Tit Monday.

( Je suis un vagabond is an unfunny, up your own arse middle class knob, Wed 12 May 2010, 10:07, 2 replies)

Even though I hate the words....
Don't like the words "boob", "boobs" or "boobies" but Booby Tuesday is fairly alliterative and rolls off the tongue(!)whilst also being a reference to the Rolling Stones song Ruby Tuesday.
(Barnetboy, Wed 12 May 2010, 10:24, closed)

I agree, although
It's hardly alliterative.
( Je suis un vagabond is an unfunny, up your own arse middle class knob, Wed 12 May 2010, 10:38, closed)

Assonant, though

( shinyshinyscalp less a man, more a way of life, Wed 12 May 2010, 14:27, closed)

Mammary Monday
Surely?
(Bonzodog29 is an unemployed sponge of the worst kind, Wed 12 May 2010, 10:38, closed)