Pope Francis has added this Day of Prayer to the universal calendar.  In a letter of announcement, the Holy Father indicated that this initiative “offers to individual believers and to the community a precious opportunity to renew our personal participation in this vocation as custodians of creation, raising to God our thanks for the marvelous works that He has entrusted to our care, invoking his help for the protection of creation and his mercy for the sins committed against the world in which we live.”  References to the blessings of creation make Eucharistic Prayer IV a particularly appropriate choice for celebrations of Mass on this day.