"Newman's Day," a tradition Princeton University, is essentially a day where students are challenged to drink a beer an hour for 24 hours. The date of this event seems to be April 24th -- in 2004 the date is on a Saturday (I could not confirm that it is April 24 every year, but the fact that it's on a Saturday sometimes indicates that it is not on the same day of the week every year because most students involved in the tradition like it when the challenge is to make it through classes while completely trashed - so why have it on a Saturday unless you have a specific date to adhere to?).
The origin of this tradition can be attributed to a jocular quote associated with actor Paul Newman: "24 beers in a case, 24 hours in a day. Coincidence? I think not."
In 2004, Paul Newman spoke out, perhaps out of guilt for being the originator of the quote, against "Newman's Day," urging students not to drink a beer an hour for a day. Another reason he's against it is because his son died of a drug overdose. Students have, in the past, shown up drunk for classes, even having beer in coffee mugs. He is not alone in considering this celebration a potentially dangerous activity.
A fact that should not surprise anybody is that Newman's Day is sponsored largely by fraternities that are not officially recognized by the University.