The Lectionary is a schedule of selected Bible readings that the Roman Catholic Church and many churches follow for worship services.
It is arranged in two cycles, a 2-year cycle for weekdays and a 3-year cycle for Sundays. Weekdays include three passages - a passage from either Testament, a Psalm, and a Gospel passage.
Sundays include these same types plus a fourth passage usually drawn sequentially from the New Testament. The Sunday 3-year cycle follows the synoptic Gospels.
Year A = Matthew
Year B = Mark
Year C = Luke
John is read during the Easter season in all three years.
The Lectionary covers 90% of the Gospels, 55% of the rest of the New Testament, 127 Psalms and 13.5% of the rest of the Old Testament. (source: https://catholic-resources.org/Lectionary/Statistics.htm)
While it doesn’t exhaust the entire Bible, the Lectionary is the most universal daily Bible-reading plan out there, which makes it a great for fellowship, since Christians all over the world use it for daily prayer and worship.
The Lectionary Reading Record is a helpful tool for following the Scripture readings used in the daily mass. It also helps a person become consistent in their daily intake of Scripture.