As a Christianfeast day:

SaintJohn Cassian, February 29in the Orthodox church

Christian feast day honoring Saint John Cassian, observed on February 29 by Eastern Orthodox churches.
Saint John Cassian was a 5th-century Christian monk and theologian whose writings on asceticism greatly influenced Western monasticism. In the Orthodox liturgical calendar, his feast is celebrated on February 29 during leap years, marking the rarity of this date. Communities commemorate his legacy through special services featuring hymns, prayers, and readings from his works. His major writings, including the Institutes and the Conferences, offer insights into communal monastic life and spiritual practice. The observance underscores his emphasis on prayer, solitude, and the transformative power of community life. Centuries later, Cassian's teachings continue to inspire monastics and laypersons seeking deeper spiritual discipline.
feast day John Cassian February 29

SaintJohn Cassian

Feast day honoring Saint John Cassian, early 5th-century monk and spiritual writer, observed on February 29 in the Orthodox Church.
Saint John Cassian founded monastic communities in southern Gaul and authored seminal texts on asceticism and communal spirituality. His writings, including the Institutes of the Coenobia and the Conferences, became foundational for Western monastic practice. Cassian emphasized the balance between prayer, work, and community life, influencing generations of monastics. The Orthodox Church commemorates his memory on February 29 during leap years, reflecting the unique rarity of the date. Liturgical services feature readings from his works, hymns, and prayers celebrating his contributions to Christian monasticism. Cassian's legacy endures as a guide for spiritual discipline and the pursuit of inner transformation.
John Cassian