A little while ago I made a catty crack about Orthodoxophile Anglicans who go a bit light on observing the traditional Byzantine fasts. Perhaps I could balance it by pointing out that Western Traditionalists have a similar question to answer. Why are we so shy of taking seriously all those vigils in the old Western rites, the days preceding festivals? The question might, for example, be put to members of the Prayer Book Society whether they observe the 16 fasting vigils which the Prayer Book orders to be kept in addition to Lent and Fridays. Keen devotees of our Lady might ask ourselves whether a new devotion for us to adopt might be fasting on the vigil of the Assumption. Easterners, as I observed before, fast for a forthight before the festival and in some places give a Lenten character to the Liturgy. In some places, the Eve of the Dormition is celebrated with a Service of the Burial of our Lady, based on the rites used in Holy Week to commemorate the Burial of our Redeemer. A Roman version of such a celebration is described in my ORDO.
In the old texts, that day seems sometimes to have a sense of alluding to her death as a prelude to her Assumption. It is well-known that Pius XII deliberately left undecided, in the definition of 1950, whether her Assumption was preceded by a death. But the tradition of both East and West strongly suggests that it was.
I have in mind the old postcommunion for August 14: "Grant, we beseech thee, O God, thy protection to our weakness; that we who celebrate the repose [requiem] of the holy Mother of God, by the help of her intercession may rise from our iniquities".