May 24 is important for each of us - it is the Day of Slavic Writing. 

This is the day of remembrance of two people who made a huge impact on the development of Slavic culture. They have the merit of creating the Slavic alphabet, without which it was impossible to translate sacred books into Slavic languages and preserve the culture of the Slavs for future generations/ 

These people are called Cyril and Methodius. They were originally from a Greek city - Byzantium. For their work in creating letters that convey Slavic sounds, the Orthodox and Catholic Churches venerate them as saints equal to the apostles.