The Solemnity of Our Lord Jesus Christ, King of the Universe, commonly referred to as the Feast of Christ the King, is a relatively recent addition to the Western liturgical calendar, having been instituted in 1925 by Pope Pius XI for the Roman Catholic Church. In 1970 its Roman Catholic observance was moved to the final Sunday of Ordinary Time.
Therefore, the earliest date on which it can occur is 20 November and the latest is 26 November. Traditional Catholics observe it on its original date, the last Sunday of October. The Anglican, Lutheran, and many other Protestant churches adopted it along with the Revised Common Lectionary, occasionally referring to it as Christ the King Sunday. It is also observed on the same computed date as the final Sunday of the ecclesiastical year, the Sunday before the First Sunday of Advent, by Western rite parishes of the Russian Orthodox Church Outside Russia.[1] Roman Catholics adhering to the Extraordinary Form of the Roman Rite as permitted under the motu proprio Summorum Pontificum use the General Roman Calendar of 1960, and as such continue to observe the Solemnity on its original date of the final Sunday of October. In 2018, it is celebrated on 25 November.[2]
Source ::wikipedia