If anyone wishes to recite or to follow the public services of the Church of England, then (in theory, at any rate) two volumes will be sufficient -- the Bible and the Book of Common Prayer; similarly in the Roman Catholic Church he requires only two books -- the Missal and the Breviary; but in the Orthodox Church, such is the complexity of the services that he will need a small library of some nineteen or twenty substantial tomes.
These books, at first sight so unwieldy, are one of the greatest treasures of the Orthodox Church. In these twenty volumes are contained the services for the Christian year -- that annual sequence of feasts and fasts which commemorates the Incarnation and its fulfilment in the Church.
The ecclesiastical calendar begins on 1 September. Pre-eminent among all festivals is Pascha (Easter), the Feast of Feasts, which stands in a class by itself. Next in importance come the Twelve Great Feasts.
Thus three of the Twelve Great Feasts depend on the date of Easter and are 'movable', the rest are 'fixed'. Eight are feasts of the Saviour, and four are feasts of the Theotokos (Mother of God).
There are also a large number of other festivals, the more prominent are:
Besides feasts, however, there are fasts. The Orthodox Church, regarding man as a unity of soul and body, has always insisted that the body must be trained and disciplined as well as the soul. 'Fasting and self-control are the first virtue, the mother, root, source, and foundation of all good".
There are four main periods of fasting during the year:
In addition to these four chief periods, most Wednesdays and Fridays -- and in some monasteries Mondays as well -- are fast days (except between Christmas and Epiphany, during Easter week, and during the week after Pentecost). The Exaltation of the Cross, the Beheading of Saint John the Baptist, and the eve of Epiphany are also fasts.
The rules of fasting in the Orthodox Church are of a rigour which will astonish and appal many western Christians. On most days in Great Lent and Holy Week, for example, not only is meat forbidden, but also fish and all animal products (lard, eggs, butter, milk, cheese), together with wine and oil.
When all relaxations and dispensations are taken into account, it remains true that Orthodox Christians in the twentieth century -- laymen as well as monks -- fast with a severity for which there is no parallel in western Christendom, except perhaps in the strictest Religious Orders.
The Church's year, with its sequence of feasts and fasts, is something of overwhelming importance in the religious experience of the Orthodox Christian.
Adapted from The Orthodox Church