Determination of the day of the week day of the week begins by starting from an ‘anchor date’: a known pair (such as January 1, 1800 as a Wednesday), determining the number of days between the known day and the day that you are trying to determine, and using arithmetic modulo 7 to find a new numerical day of the week. One standard approach is to look up (or calculate, using a known rule) the value of the first day of the week of a given century, look up (or calculate, using a method of congruence) an adjustment for the month, calculate the number of leap years
Three-Day Week Three-Day Week The Three-Day Week was one of several measures introduced in the United Kingdom by the Conservative Government to conserve electricity, the generation of which was severely restricted owing to industrial action by coal miners. The effect was that from 1 January until 7 March 1974 (also the same month the 1973-74 oil crisis ended) commercial users of electricity were limited to three specified consecutive days' consumption each week and prohibited from working longer hours on those days. Services deemed essential (e.g. hospitals, supermarkets and newspaper prints) were exempt. Television companies were required to cease broadcasting at 10:30 p.m.