There are two kinds of synaxaria - simple synaxaria, which are merely lists of the saints arranged in the order of their anniversaries, e.g.
The list of anniversaries of a church formed its Martyrology.
In the early days each church confined itself to celebrating its own martyrs; but it was not long before it became customary to celebrate the anniversaries of martyrs of other churches.
Apparently they were at first arranged in a series of anniversaries separate from that of the martyrs, as seems to be shown by the existence at Rome of the Depositio episcoporum side by side with the Depositio martyrum; the two lists seem to have been combined, as in the calendar of Carthage, which includes the dies nataliciorum martyrum et depositiones episcoporum.
REQUIEM, the name of a solemn mass for the dead (Missa pro defunctis) in the Roman Church, appointed 'to be sung on All Souls' Day, in memory of all "faithful departed," at funeral services, and at the anniversaries of the death of particular persons.
431) concurs - his custom being to visit Ostia each year, and Rome on the apostolic anniversaries (Ep. 20, 2; 45, r).
In 1868 he issued the next collection in Under the Willows and other Poems, but in 1865 he had delivered his "Ode recited at the Harvard Commemoration," and the successive centennial historical anniversaries drew from him a series of stately odes.
Of the various orations (among others one by Edward Everett in 1825) that have been delivered at Concord anniversaries perhaps the finest is that of George William Curtis, delivered in 1875.
It was not pretended that the apostles had legislated on the matter, but the general and natural feeling that the anniversaries of the crucifixion and the resurrection of Christ ought to be celebrated by Christians took expression in a variety of ways according to the differing tastes of individuals.