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
Four-day week the state expected to save on operating costs such as electricity, heat, air conditioning, and gasoline for state-owned vehicles. Utah ended this practice however, in 2011, with the Utah Legislature overriding Governor Gary Herbert's veto of five-day work week legislation. Many local governments have had alternative schedules for many years. Public schools in Hawaii closed on 17 Fridays in 2010. Over 100 school districts in rural areas in the United States changed the school week to a four-day week; most also extended each school day by an hour or more. The changes were often made in order to save money