Mardi Gras
February 24, 2009
Easter occurs each year on the first Sunday after the first full moon after the vernal equinox. Mardi Gras occurs on the Tuesday of the seventh week before Easter. Mardi Gras falls on February 24th in 2009, with Easter forty-seven days later on April 12th. On what date did Mardi Gras fall in 1989? On what date will Mardi Gras fall in 2049?
Programming Praxis 
https://github.com/ftt/programming-praxis/blob/master/20090224-mardi-gras/mardi-gras.py