Southern Comfort wrote:Actually it's more complicated than that. The Baptism of the Lord is the last day of the Christmas season, but it is also the 1st Sunday of Ordinary Time, which begins at the same time.
What's your source for this, SC? I expect it's one of those things where different documents contradict each other once you look closely enough.
The Missal seems fairly unambiguous, though: Ordinary Time begins on the Monday which follows the Sunday occurring after 6 January
(Universal Norms on the Liturgical Year, 44).
Try Lectionary Vol I, p. 639. The heading at the top of the page says unambiguouslyFirst Sunday in Ordinary Time
THE BAPTISM OF THE LORD
Same thing happens on pp. 735 and 833 (Years B and C).
It's similar to Christ the King in all three years of the cycle, which carries the headingLast Sunday in Ordinary Time
OUR LORD JESUS CHRIST, UNIVERSAL KING
The only difference is that Christ the King is a solemnity and the Baptism of the Lord is a feast. Apart from that, typographically they are identical.
However, in the General Introduction to the Lectionary for Mass
, section 5 (Ordinary Time), subsection a, para 103 indeed begins "Ordinary Time begins on the Monday after the Sunday following 6 January....."
para 104, subpara 1, begins "The Sunday on which the feast of the Baptism of the Lord falls replaces the first Sunday of Ordinary Time...."
In the Missal itself, on page 498 we read that Ordinary Time "begins on the Monday following the Sunday after 6 January", but on the facing page, under the heading "FIRST WEEK IN ORDINARY TIME", we read "On the first Sunday in Ordinary Time there occurs the Feast of the Baptism of the Lord, pp.
The reason for this is that the 1st Sunday in Ordinary Time is the feast of the Baptism of the Lord, but on the remaining weekdays of the 1st week the formulary on page 499 is used. (Normally weekdays in OT simply repeat the formulary of the preceding Sunday.)
In other words, the whole thing is a total mess. I stick by my opinion that this day is both
the end of the Christmas Season and
the 1st Sunday of Ordinary Time.