Holy Week by some parishes of the Roman Rite of the Catholic Church, of the Polish National Catholic Church, of Anglicanism, of other Protestant churches such as Lutheranism, and of Western Rite Orthodoxy within the Eastern Orthodox Church. In the Catholic Church, "tenebrae" is the name given to the celebration, with special ceremonies, of Matins and Lauds, the first two hours of the Liturgy of the Hours, of the last three days of Holy Week. Maundy Thursday (also known as Holy Thursday) commemorates the Last Supper, where Christ lays out the model for the Eucharist or Holy Communion. During the meal, Jesus
Determination of the day of the week the intended design objective. The tabular forerunner to Tøndering's algorithm is embodied in the following K&R C function. With minor changes, it was adapted for other high level programming languages such as APL2. Posted by Tomohiko Sakamoto on the comp.lang.c Usenet newsgroup in 1992, it is accurate for any Gregorian date. IBM's Rata Die method requires that one knows the "key day" of the proleptic Gregorian calendar i.e. the day of the week of January 1, AD 1 (its first date). This has to be done to establish the remainder number based on which the day of the week is