Foot washing "mandatum" (maundy), therefore, was applied to the rite of foot-washing on this day of the Christian Holy Week called Maundy Thursday. John 13:1–17 recounts Jesus' performance of this act. In verses 13:14–17, He instructs His disciples: Many denominations (including Anglicans, Lutherans, Methodists, Presbyterians, Mennonites, and Catholics) therefore observe the liturgical washing of the feet on Maundy Thursday of Holy Week. Moreover, for some denominations, foot-washing was an example, a pattern. Many groups throughout Church history and many modern denominations have practiced foot washing as a church ordinance including Adventists, Anabaptists, Baptists, and Pentecostals. The origin of the word "Maundy" has
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