Holy Week XII. In this Mass, the bishop blesses separate oils for the sick (used in Anointing of the Sick), for catechumens (used in Baptism) and chrism (used in Baptism, but especially in Confirmation and Holy Orders, as well as in rites such as the dedication of an altar and a church). Tenebrae (Latin for "shadows" or "darkness") is celebrated within Western Christianity on the evening before or early morning of Maundy Thursday, Good Friday, and Holy Saturday. Tenebrae is distinctive for its gradual extinguishing of candles while a series of readings and psalms is chanted or recited. Tenebrae services are celebrated
Adoption of the Gregorian calendar 12 days, only 11 were skipped, and the day of the week was repeated on successive days, because at the same time the International Date Line was moved, from following Alaska's eastern border with Canada to following its new western border, now with Russia. Many of the countries of eastern Europe were Eastern Orthodox or Islamic and adopted the Gregorian calendar much later than western Christian countries. Roman Catholic countries such as the Polish–Lithuanian Commonwealth adopted the "new style" (N.S.) Gregorian calendar in 1582 (switched back in 1795 after Third Partition of Poland), but the switch to the Gregorian calendar