Eastertide is the period of fifty days from Easter Sunday to Pentecost Sunday
The Octave of Easter: This octave is part of the Easter Solemnity, Paschal Tide & commences with the First Vespers of Low Sunday and ends before the First Vespers of Trinity Sunday.
The Sundays from Easter to Ascension Day, besides being called the First, Second (etc.) Sunday after Easter, have their own peculiar titles.
Quasimodo Sunday & Bright Week
The first is the "Dominica in albis", or Low Sunday. In the Dioceses of Portugal and Brazil (also in the ecclesiastical province of St. Louis, Mo.) on the Monday after Low Sunday is celebrated the feast of the Joys or Exultation of Mary at the Resurrection of her Son (double of the second class). The Russians, on Tuesday of this week, celebrating Radonitsa, go in procession to the cemeteries and place Easter eggs on the graves
Misericordias Domini & Sunday of the Divine Mercy
In the Latin Church the second Sunday is called from its Gospel the Sunday of the Good Shepherd and from the Introit "Misericordias Domini"; in many dioceses (Seville, also with the order of the Capuchins) it is called the feast of Our Lady Mother of the Good Shepherd (double second class); at Jerusalem and in the churches of the Franciscans it is called the feast of the Holy Sepulchre of Christ; in the Greek Church it is called ion myrophoron (Sunday of the women who brought ointments to the sepulchre of Christ); the Armenians celebrate on this Sunday the dedication of the first Christian church on Mount Sion.
The third Sunday is called from the Introit "Jubilate" and the Latin Church has assigned to it the feast of the Patronage of St. Joseph (double second class); the Greeks call it the Sunday of the Paralytic, from its Gospel.
Cantate Sunday or Rose Sunday
The Oriental Churches on Wednesday after the third Sunday celebrate with a very solemn Office and an octave, the Mesopentekoste, the completion of the first half of Paschal Tide; it is the feast of the manifestation of the Messiah, the victory of Christ and the Church over Judaism ["Zeitschrift für katholische Theologie" (1895), 169-177]; the Slav nations in this day have a solemn procession and benediction of their rivers. The fourth Sunday is called Cantate Sunday; by the Orientals it is called Sunday of the Samaritan Woman.
The fifth Sunday, "Vocem jucunditatis" in the Orient, Sunday of the Man Born Blind. In the Latin Church follow the Rogation Days; in the Greek Church on Tuesday is kept the apodosis or conclusion of the feast of Easter. The Greeks sing the Canons of Easter up to this Tuesday in the same manner as during Easter Week, whilst in the Latin Church the specific Easter Office terminates on Saturday following the feast. Thursday is the feast of the Ascension. The Friday of this week, in Germany, is called "Witterfreitag"; the fields are blessed against frost and thunderstorms.
Sunday within the octave of Ascension is called "Exaudi" from the Introit; in some dioceses it is called Feast of Our Lady, Queen of the Apostles (double major) or of the Cenacle (Charleston and Savannah, first class); in Rome it was called Sunday of the Roses ("Pascha rosarum" or "rosatum"), since in the Pantheon rose-leaves were thrown from the rotunda into the church; in the Greek and Russian Churches it is the feast of the 318 Fathers of the first Nicene Council; the Armenians call it the "second feast of the flowers", a repetition of Palm Sunday. By older liturgists the week before Pentecost is called "Hebdomada expectationis", week of the expectation of the Holy Ghost. On the Vigil of Pentecost the baptismal water is blessed in the Latin Church; in the Oriental Churches it this Saturday is the psychosabbaton (All Soul's Day); on this day the Greeks bless wheat cakes and have processions to the cemeteries.