The Easter Octave is one of the lesser known liturgical celebrations in the Catholic Church. It includes both Easter Sunday and the seven days that follow, culminating in the celebration of Divine Mercy Sunday (A.K.A the Second Sunday of Easter).
Christians started to extend certain feasts beyond the initial day beginning from at least the 3rd or 4th century, . This came to mean that the joyous celebrations of Easter Sunday were extended and lasted for a full eight days.
In fact, Christians used to treat each day in the octave as if it were Easter Sunday. This tradition has been kept by the Roman Rite and many of the Eastern Rites, where the liturgical readings and actions of each day portray what happened on Easter Sunday.
The Daily Missal of St. Andrew further explains the connection the Easter Octave had to the newly baptized members of the Catholic Church.
The Missal explained that during the Octave of Easter, during which formerly no servile work was done, only continual feast. Each day the newly baptized attended Mass at a [different church in Rome], at which they received Holy Communion. Moreover, the newly baptized would wear their baptismal gowns during the entire Easter octave.
As these particular baptismal traditions are no longer being practiced by the Catholic Church, the Octave of Easter still remains a celebratory time for Christians around the world and is supposed to be a joyous time to remain in the beauty of the resurrection of our Lord.
Similarly, with the Christmas celebration in the Catholic Church, the Easter season only begins with Easter Sunday. Because Easter is a season for feasting, praising God and enjoying the company of family and friends.
The fasting days of Lent are gone! Now is a time to feast!