But in Gondor the New Year will always now begin upon the twenty-fifth of March when Sauron fell, and when you were brought out of the fire to the King.
- Gandalf in the Return of the King

In "The Lord of the Rings", March 25 is the day of the fall of Sauron and his realm. In honour of this event, to encourage the reading of J.R.R. Tolkien's works, this date has been declared as Tolkien Reading Day.
I celebrate by working on some new Middle-Earth inspired projects, and, of course, by reading my favourite passages... Like this one:

For myself, I would see the White Tree in flower again in the courts of the kings, and the Silver Crown return, and Minas Tirith in peace: Minas Anor again as of old, full of light, high and fair, beautiful as a queen among other queens; not as a mistress of many slaves, nay, not even a kind mistress of willing slaves. War must be, while we defend our lives against a destroyer who would devour all; but I do not love the bright sword for its sharpness, nor the arrow for its swiftness, nor the warrior for his glory. I love only that which they defend: the city of the Men of Númenor, and I would have her loved for her memory, her ancientry, her beauty, and her present wisdom. Not feared, save as men may fear the dignity of a man, old and wise.
So fear me not! I do not ask you to tell me more. I do not even ask you to tell me whether I now speak nearer the mark. But if you will trust me, it may be that I can advise you in your present quest, whatever that be yes, and even aid you.

Cuio i Pheriain anann! Aglar'ni Pheriannath!
How do you celebrate?  What are you reading today? :)