Feast Day: February 14

Memorial of the ninth-century brothers from Thessalonica known as the Apostles to the Slavs. Saint Cyril developed the Glagolitic alphabet to translate the liturgy and Scriptures into Slavonic. Co-patrons of Europe with Saint Benedict (USCCB Liturgical Calendar 2026).

Memorial of the ninth-century brothers from Thessalonica known as the Apostles to the Slavs. Saint Cyril developed the Glagolitic alphabet to translate the liturgy and Scriptures into Slavonic. Co-patrons of Europe with Saint Benedict (USCCB Liturgical Calendar 2026).

From the USCCB 2026 Liturgical Calendar.