It seems fitting to mark the day with the prayer from the end of the Proslogion (I am using Hopkins's translation).
O God, I pray, let me know and love You, so that I may rejoice in You. And if I cannot in this life [know, love, and rejoice in You] fully, at least let me advance day by day until the point of fullness comes. Let knowledge of You progress in me here and be made full [in me] there. Let love for You grow [in me here] and be [made] full [in me] there, so that here my joy may be great with expectancy and there may be full in realization. O Lord, You command—or, rather, You counsel—[us] to ask through Your Son; and You promise [that we shall] receive, so that our joy may be full. O Lord, I ask for what You counsel through our marvelous Counselor; may I receive what You promise through Your Truth, so that my joy may be full. O God of Truth, I ask; may I receive, so that my joy may be full. Until then, may my mind meditate upon [what You have promised]; may my tongue speak of it. May my heart love it; may my mouth proclaim it. May my soul hunger for it; may my flesh thirst for [it]; may my whole substance desire [it] until such time as I enter into the joy of my Lord, the trine and one God, blessed forever. Amen.
