Casimir Pulaski Day takes place on March 06, 2023. Casimir Pulaski Day is a holiday observed in Illinois on the first Monday of every March in memory of Casimir Pulaski (March 6, 1745 - October 11, 1779), a Revolutionary War cavalry officer born in Poland as Kazimierz Pulaski. He is known for his contributions to the U.S. military in the American Revolution by training its soldiers and cavalry. While it is a legal holiday only in Illinois, Casimir Pulaski Day is also observed in other states, especially among Polish-American communities. The celebrations take place as group gatherings, ceremonies or parades.