Greetings in that Divine and Most Precious Name of Our Lord and Savior Jesus Christ!
I don't believe there is any Liturgy celebrations. The Day of Praise is a kind of conference, or in good ol Baptist nomenclature, a revival. Different churches are sending choirs to sing hymns in their own languages and melodies, so we can share our faith through simple and joyful fellowship. No polemics, no politics, just praises, hence the "day of praise." I'm not even sure if there are any sermons or speakers. Either way, it should be a delight to have such pan-Oriental Orthodox fellowship with a few visiting EO.