The aim of The Proper of Time in the Post-Vatican II Liturgical Reforms is to allow easy comparison of the work of the Consilium ad exsequendam Constitutionem de Sacra Liturgia on the prayers of the Roman Missal with those found in the 1962 Missal and the 1970/2002 Missal.

The Consilium ad exsequendam Constitutionem de Sacra Liturgia, better known as the Consilium, was the body that, during the Second Vatican Council, was made responsible for the reform of the liturgy that was desired by the Constitution on the Liturgy (Sacrosanctum Concilium). One of the various documents of Group 18 of the Consilium, Schema 186, deals with the reform of the various prayers (collects, prayers over the gifts, etc.) contained in the Proper of Time of the Roman Missal, and gives draft texts for each day in this section. The prayers of the Ordinary and Extraordinary Forms of the Roman Rite are, in many places, very different. In recent years, these differences and the work of the Consilium have increasingly been the object of scholarly study and enquiry. Now, in The Proper of Time in the Post-Vatican II Liturgical Reforms, the corpus of orations in Schema 186 are readily available for the first time, and have been arranged side-by-side in parallel with those of the 1962 and 1970/2002 Missals for easy comparison. Various tools and indices are also provided in the book to aid further study and research into this important aspect of the post-Vatican II liturgical reforms.