Today is the third Thursday after Pascha, Holy and Great Easter Sunday. The Church today commemorates the appearance of the Precious Cross in the sky above Jerusalem in the fourth century.
On this day in the year 351, not long after Cyril succeeded Maximus as Archbishop of Jerusalem, and during the reign of Constantius, the son of St. Constantine the Great, on the day of Pentecost, the sign of the Cross appeared over Jerusalem.