Octoechos
Octoechos is the name of a service-book used in the Greek Church. It consists of two volumes (folio), and contains the particular hymns and services for every day of the week, a portion of the daily service being appropriated to some saint or festival besides those marked in the calendar. Thus, Sunday is dedicated to the resurrection; Monday, to the angels; Tuesday, to St. John the Baptist; Wednesday, to the Virgin and the cross; Thursday, to the apostles; Friday, to the Savior's passion; and Saturday, to saints and martyrs. The prayers being intoned in the Greek Church, the Octcechus enjoins which of the eight ordinarily in use is to be employed on different occasions and for different services.