Celebrated on May 24

"Saints Cyril and Methodius Day" is a holiday, usually celebrated on May 24 in countries which observe Eastern Orthodox tradition, and on July 5 in countries that observe Roman Catholic tradition. It commemorates the creation of the Slavic Glagolitic alphabet and the spreading of the Christianity on Slavic by the brothers Saints Cyril and Methodius from Salonica. There is evidence that the Cyrillic alphabet was not created by Cyril and Methodius but by their pupil, Saint Clement of Ohrid, but the alphabet bears Cyril's name in honor of St. Clement’s teacher. The celebration also commemorates the introduction of literacy and the preaching of the gospels in the Slavonic language by the brothers.

In the Republic of Macedonia, it is celebrated on May 24 and is known as the "Saints Cyril and Methodius, Slavonic Enlighteners' Day", a national holiday. The Government of the Republic of Macedonia took the decision for the statute of national holiday in October 2006. Before that it was celebrated only in the schools. It is also known as the day of the "Solun Brothers".