Orthros is the longest and most complex of the daily cycle services.
There are seven types of Orthros:
- Sunday Orthros: the longest of the regular orthros services. If this service is celebrated in its entirety it can last up to three hours. It contains three canons, apart from any additional festal cannons which may be added. As a result, in most practical situations, abbreviations are made. Often, this Orthros is part of a vigil.
- Daily Orthros: there is no Gospel.
- Feast-day Orthros with Gospel.
- Lenten Orthros: penitential material added (hymns and prayers).
Orthros services related to the Paschal feast:
- Great and Holy Friday Orthros: there are twelve Gospel lessons; Antiphons are used (originating in a different office). The troparion sung at the 15th antiphon: Today is hung upon the cross... (Simeron krematai).
- Great and Holy Saturday Orthros. This contains some elements of the old cathedral office: procession with epitaphios, reading of three pericopes (OT, epistle, Gospel) at the end.
- Paschal Orthros. This is celebrated from Pascha Sunday until Thomas Sunday. The six psalms and the praises are not part of this service.