I am hard pressed to understand the logic of why the Feast of the Body and Blood of Christ is celebrated when it is. There may be a very good reason and if anybody knows I would be interested. But I am glad there is such a feast.
There is another similar day – Maundy Thursday. (Oh! Maybe THAT’S why it is on a Thursday – save for places where it is moved to Sunday.) Anyway, Maundy Thursday (or Holy Thursday) is the day we celebrate the institution of the Blessed Sacrament. But there is also a ton of other things going on that day and the theme one of mourning. Here we have Jesus and precious little time to spend in devotion of His presence among us in this most august way. So in the 12th century a movement was begun to have a day when we could, in a special and devotional way, show our love and gratitude for such an auspicious gift. Pope Urban IV began the feast day and St. Thomas Aquinas wrote the liturgical texts. He also wrote some songs about the Blessed Sacrament the words of which we still sing today at benediction: O Salutaris (O Saving Victim) and Tantum Ergo (Down In Adoration).