THE SUNDAYS OF THE ECCLESIASTICAL YEAR
In the Old Testament God commanded the Jews to observe one holyday a week. This day was Saturday, a day of rest excluding work, but during this day the Jews were required to take active part in divine services.
In the New Testament the weekly holyday became Sunday. The first Christians observed every Sunday in memory of Jesus Christ Who arose from the dead on a Sunday. Sunday has become known among the various peoples of the world as "the day of the sun", "the Lord's day", and "the Resurrection" because Christ is the sun of our spiritual life and Our Lord and Master.
The Ukrainian word "nedila" (Sunday) comes from the fact that on that day it was forbidden to act ("ne-dila") or ("not to act"), for it is a day of rest. There are 52 Sundays in the Church Year. A Christian is obliged to observe Sundays by going to church, assisting at Mass, and adoring God. Every Sunday is Our Lord's Feast Day, but the most important Sunday of all is Easter Sunday for this is the Feast of Christ's Resurrection. Easter Sunday is observed by the Church in the spring. More accurately, this Feast is celebrated on the Sunday following the first new moon after the vernal equinox, which is March 21st. If the Jewish Passover coincides with the Christian Easter, then it is carried over to the following Sunday. Since a full moon in the spring can occur only between March 21st and April 18th, then the earliest possible date for Easter is March 22nd and the latest possible date is April 25th. This is the reason why Easter falls on different dates during the years. Upon the date of Easter depends the whole Easter Cycle, that is, the complete series of Sundays which precede Easter as well as the series of Sundays which follow Easter.