Hi,
It's not Monday nor Tuseday but Thursday.  Green beer day is celebrated always on the last Thursday just B4 the Spring break. 
Best regards,

Here is a short quote (from Wikipedia): "Green Beer Day is a holiday celebrated by students at Miami University in Oxford, Ohio. It is celebrated on the Thursday before Spring Break every March. The holiday begins at 5:30am when the bars open to serve green-colored beer, shots, and cocktails to waiting Miami students (The state of Ohio forbids bars from serving alcoholic beverages before 5:30 am.)"