Dear Friends in Christ,
The liturgical calendar of the Catholic Church assigns solemnities, feasts, and memorials to fixed dates in the solar calendar, and those celebrations are kept each year on the same assigned date. For example, 28 June – which falls this year on a Thursday – is the memorial of St Irenaeus of Lyons, a bishop and martyr who died in the year 202, and no matter on which day of the week it falls, the memorial of St Irenaeus is always kept on 28 June. Except if it falls on a Sunday.
Every Sunday of the year is a solemnity of the Resurrection of the Lord Jesus – a little Easter, and for this reason, almost no liturgical celebrations take the place of the normal Sunday observance. But there are a few exceptions to that rule. The Presentation of the Lord Jesus in the Temple is on 2 February, and if that date falls on a Sunday in a given year, the Presentation takes precedence. So too do the Solemnities of Saints Peter and Paul on 29 June, the Transfiguration of the Lord on 6 August, the Exaltation of the Holy Cross on 14 September, and the Dedication of the Lateran Basilica (the Cathedral Church of Rome) on 9 November. And to that list we must add today’s solemnity: the Nativity of St John the Baptist.
If this Sunday were not 24 June, then it would simply be the 12th Sunday in Ordinary Time, also called the 12th Sunday of the Year. But because today is 24 June, we keep instead the liturgical celebration of the birth of the cousin and forerunner of the Lord, St John the Baptist. But why is the feast of the birth of John the Baptist always on 24 June? Because Holy Scripture tells us that John was conceived and therefore born six months before the Lord Jesus, and Christmas Eve is six months from today.
Speaking of the Lord Jesus and of himself, John the Baptist said, “He must increase; I must decrease.” (John 3.30) For this reason St Augustine found it particularly appropriate that the births of John and the Lord Jesus should be celebrated so near the summer and winter solstices. The nights begin to grow longer as we remember the birth of John, and the days begin to grow longer when we rejoice in the birth of Christ.
But even these considerations do not tell why the birth of John the Baptist should replace the usual Sunday celebration when 24 June coincides with the Lord’s Day, and for that explanation we turn to the Savior himself. When asked about the prophecy that Elijah must precede the coming of the Messiah, the Lord Jesus explained that Elijah’s mission was fulfilled by John the Baptist, whom Christ called the greatest man of woman born. And it was John who both baptized the Lord Jesus and then pointed to him with saving faith: Behold, the Lamb of God!