Great Lent is the longest and most solemn fast of the Orthodox year: forty days of repentance, prayer, and self-denial that prepare the faithful for Holy Week and Pascha. It is not a season of gloom but of clarification, a stripping-away of what distracts, so that the heart can be turned again toward God and the Resurrection can be met with a readied soul.
The fast has three strands the Fathers always keep together: prayer, fasting, and almsgiving. To eat more simply while praying more and giving more is the whole shape of it; fasting from food without fasting from anger and greed, St John Chrysostom warns, profits nothing. The services grow longer and more penitential, the great Canon of St Andrew is read, and the Church sings, again and again, the prayer of St Ephrem.
The dates of Great Lent move with Pascha, beginning on Clean Monday, seven weeks before the feast. As with every fast, the measure is not a law to be gripped but a gift to be received: the exact keeping of it is set with one's priest, according to one's strength and state of life.