Hi, I received a Latin/English daily Missal from 1961. It does not appear to follow the 3-year lectionary cycle. There is only one set of readings for a given day. Was the 3-year cycle introduced after Vatican II?
Yes, the 3-year Lectionary cycle that is now is use came about from the Second Vatican Council. The revision of the Lectionary was part of the overall reform of the Liturgy that the Council undertook. The Latin edition appeared in 1969 and the USA’s approved Lectionary began on the First Sunday of Advent, Nov. 30, 1970.
There have been new translations of the readings and feast days added over the decades since then, but the basic 3 year cycle format is a product of the Second Vatican Council.