All I can see online is that March 28th is "Serfs Emancipation Day" in China, the 51st anniversary of the Chinese government's dissolution of the Central Tibetan Administration, the government headed by the Dalai Lama which had ruled Tibet for nearly 400 years. Therefore this is also the 51st anniversary of the Central Tibetan Administration's government in exile.
EDIT: Hmm, my posting history says I posted #2790 on 3/27 and post 2791 on 3/30. I guess I missed it last year.
I will spare you AND our bandwidth a post containing all 359 graphics which popped the top of our site in 2007, but if you're interested, you can plug your favourite dates into http://the-w.com/images/2007/07xxxx.jpg and pull them down on your own.