The main focus of this period lies on the feast of Christmas itself, of course. It is celebrated on the 25th of December and commemorates the birth of Christ. This feast is prepared during the 4 preceding weeks, a period referred to as Advent. The actual Christmastide starts with Christmas. The old calendar featured the feast of the Circumcision on the 1st of January and the feast of Epiphany (the visit of the 3 Magi) on the 6th of January. Nowadays, the first day of the New Year is reserved for Mary, in her capacity of the Mother of God. Epiphany was moved to the Sunday closest to the 6th of January. Furthermore, the Christmastide includes the feasts of those saints closely related to the events in Bethlehem, such as St. Stephen, the first martyr (26th of December), St. John the Apostle (27th of December) and of course Holy Innocents' Day (28th of December). In all, the Christmastide stretches from the first Sunday of Advent up to and including the 13th of January. The following Sundays until the beginning of Lent are taken from the so-called Ordinary time.
¶Once again, the name says it all: the Eastertide is centered around the feast of Easter, commemorating Christ's resurrection. There is no fixed date for this most important feast of the liturgical year. Its date depends on the moon cycle, as was decreed by the Council of Nicea in 325. Ever since that council, Easter has been celebrated on the first Sunday after the first full moon following the beginning of spring in the Northern Hemisphere. This means that Easter can be celebrated at its earliest on the 22nd of March and at its latest on the 25th of April. Easter is preceded by a period of 40 days called Lent. This period of repent and fasting starts with Ash Wednesday and continues for 6 Sundays. The last-but-one Sunday is called Palm Sunday, the last Sunday before Easter is refered to as Passion Sunday. The week before Easter is called Holy Week, and is marked by a number of services recalling the last days of Christ. The most important are celebrated on Maundy Thursday (The last Supper), Good Friday (Crucifixion) and Holy Saturday. Easter is followed by the Easter Week and by 5 subsequent Sundays after Easter. On the Thursday following the 5th Sunday, the Church celebrates the Ascension of The Lord. This feast is followed by another Sunday after Easter, and the next Sunday is reserved for the feast of Pentecost, concluding the Eastertide.
¶With the Sunday after Pentecost, the church resumes the count of the Sundays in ordinary time, picking up where we had left between Christmas and Easter. On the Sunday after Pentecost we celebrate the feast of the Holy Trinity and the next Thursday the feast of the Holy Sacrament.