The Orthodox Church celebrates the memory of All Saints on the first Sunday after Pentecost. The need for setting aside one day in the ecclesiastical calendar to honour 'all saints' was felt right after the Persecutions. Obviously, and in spite of the fact that the Church was already celebrating the memory of well-known saints, it was impossible to know individually and by name, all those who gave themselves for the faith in Christ. And though the day of commemoration varied among the various local Churches, the faithful of the Christian Church at large felt the need not only to commemorate the life and martyrdom of those athletes of the new faith, but also to establish a communion with them.
The present day of celebration of the feast of All Saints goes back at least to St. John Chrysostom, who in one of his homilies in Constantinople says that the commemoration of the Martyrs of the Universal Church was observed on the first Sunday after Pentecost. All Saints Day has always been observed not only as an opportunity for the Church to project to her living membership Christian ideals to be emulated, but also as an opportunity to establish a unity between the Triumphant Church of Christ in heaven and His militant one on earth.