Easter ( , Pascha) is the most important annual religious feast in the Christian liturgical year. According to Christian scripture, Jesus was resurrected from the dead on the third day after his crucifixion. Christians celebrate this resurrection on Easter Day or Easter Sunday (also Resurrection Day or Resurrection Sunday), two days after Good Friday and three days after Maundy Thursday. The chronology of his death and resurrection is variously interpreted to be between A.D. 26 and 36. Easter also refers to the season of the church year called Eastertide or the Easter Season. Traditionally the Easter Season lasted for the forty days from Easter Day until Ascension Day but now officially lasts for the fifty days until Pentecost. The first week of the Easter Season is known as Easter Week or the Octave of Easter. Easter also marks the end of Lent, a season of fasting, prayer, and penance.

Easter is a moveable feast, meaning it is not fixed in relation to the civil calendar. The First Council of Nicaea (325) established that the date of Easter would be the first Sunday after the full moon (the Paschal Full Moon) following the vernal equinox. Ecclesiastically, the equinox is reckoned to be on 21 March. The date of Easter therefore varies between 22 March and 25 April. Eastern Christianity bases its calculations on the Julian Calendar whose 21 March corresponds, during the twenty-first century, to 3 April in the Gregorian Calendar, in which calendar their celebration of Easter therefore varies between 4 April and 8 May.

Easter is linked to the Jewish Passover not only for much of its symbolism but also for its position in the calendar.

Cultural elements, such as the Easter Bunny and Easter egg hunts, have become part of the holiday's modern celebrations, and those aspects are often celebrated by many Christians and non-Christians alike. There are also some Christian denominations who do not celebrate Easter.

Christian theological significance

The Christian tradition, based on New Testament and later writings, links the Last Supper with Passover. According to Paul, as Jesus prepared himself and his disciples for his death during the Last Supper, he gave the Passover meal a new meaning. states:

"Get rid of the old yeast that you may be a new batch without yeast—as you really are. For Christ, our Passover lamb, has been sacrificed"

This refers to the Passover requirement to have no yeast in the house and to Christ's identification as the Paschal lamb.

More importantly, Easter has become associated with Jesus' crucifixion, and the loaf of bread and cup of wine served at the Last Supper is identified with and symbolizing his body soon to be sacrificed and his blood soon to be shed. ( )

One interpretation of the Gospel of John is that Jesus, as the Passover lamb, was crucified at roughly the same time as the Passover lambs were being slain in the temple, on the afternoon of Nisan 14. This interpretation is often held to be inconsistent with the chronology according to the Synoptic Gospels. It assumes that "the preparation of the passover" in literally refers to Nisan 14 (Preparation Day for the Passover) and not necessarily to Yom Shishi (Friday, Preparation Day for Sabbath) and that the Pharisees' desire to "eat the passover" in refers to the hagigah offering of Nisan 15.