period, period of time, time period - an amount of time; "a time period of 30 years"; "hastened the period of time of his recovery"; "Picasso's blue period"

century - 100 years

doctrine, ism, philosophical system, philosophy, school of thought - a belief (or system of beliefs) accepted as authoritative by some group or school

New Testament - the collection of books of the Gospels, Acts of the Apostles, the Pauline and other Epistles, and Revelation; composed soon after Christ's death; the second half of the Christian Bible

anniversary, day of remembrance - the date on which an event occurred in some previous year (or the celebration of it)