The First Readings prescribed for Weekday Masses in the special liturgical seasons are the same each year:

• Season of Advent: selections from various OT books, esp. the prophet Isaiah.
• Christmas Season: continuous reading of the entire First Letter of John  (from Dec. 27 to Jan. 12; interrupted only for the Feast of Mary, Mother of God [Jan. 1], and the Feast of the Epiphany of the Lord; cf. detailed chart).
• Season of Lent: selections from a wide variety of OT books, with no connected pattern.
• Easter Season: semi-continuous readings from the Acts of the Apostles  (cf. detailed chart).

The First Readings prescribed for Weekday Masses in Ordinary Time follow a two-year cycle, with all odd-numbered years using the selections for "Year 1" and all even-numbered years using "Year 2." Semi-continuous readings are taken from various books of the Old and New Testaments. The following chart lists the biblical books and chapters from which the readings are taken for the weeks indicated. Note that most readings include only a small number of verses, not the entire chapters listed; verse numbers are not specified in this chart to provide a simpler overview of the overall patterns.

Ordinary Time, Years I & Year II

Notes:

1) The chart above provides additional information through some special features:

• light blue backgrounds indicate readings from the Old Testament/Hebrew Bible;
• light green backgrounds indicate readings from the Deuterocanonical Books of the OT;
• plain white backgrounds indicate readings from the New Testament books and epistles;
• chapter numbers in bold indicate that all or most (at least 80%) of the chapter is included in the readings;
• chapter numbers not bolded indicate that only part of the chapter is included (sometimes only a few verses).

2) Remember that this chart summarizes the readings prescribed for each week, rather than listing the six weekday Masses separately (in some weeks, fewer chapter numbers are listed since several Masses that week may have short selections from the same biblical chapter; in other weeks, more than six chapters may be listed because the readings for one or more Masses that week may include selected verses from two or more biblical chapters).

3) The introductory sections of most published Weekday Lectionaries include a similar table showing the "Order of the First Reading for Weekdays in Ordinary Time." That table can give the false impression, however, that the weekday readings include the entire biblical books listed for the two-year cycle. In contrast, the chart above more clearly shows how many chapters are not included in the prescribed readings for weekday Masses. (For example, selections from only 14 of the 40 chapters of Exodus, from only 7 of the 25 chapters of 2 Kings, and from only 2 of the 15 chapters of 2 Maccabees are included; in contrast, almost the entire Letter to the Ephesians and the entire Epistle of James are included).