Easter, annual festival commemorating the Resurrection of Jesus Christ, and the principal feast of the Christian year. It is celebrated on a Sunday on varying dates between March 22 and April 25 and is therefore called a movable feast. The dates of several other ecclesiastical festivals, extending over a period between Septuagesima Sunday (the ninth Sunday before Easter) and the first Sunday of Advent, are fixed in relation to the date of Easter.
Connected with the observance of Easter are the 40-day penitential season of Lent, beginning on Ash Wednesday and concluding at midnight on Holy Saturday, the day before Easter Sunday; Holy Week, commencing on Palm Sunday, including Good Friday, the day of the crucifixion, and terminating with Holy Saturday; and the Octave of Easter, extending from Easter Sunday through the following Sunday. During the Octave of Easter in early Christian times, the newly baptized wore white garments, white being the liturgical colour of Easter and signifying light, purity, and joy.
*Penemuruai`s comment: Easter Sunday