Names of the days of the week Meiji era. In China, with the founding of the Republic of China in 1911, Monday through Saturday in China are now named after the luminaries implicitly with the numbers. Sunday comes first in order in calendars shown in the table below. In the Judeo-Christian or Abrahamic tradition, the first day of the week is Sunday. Biblical Sabbath (corresponding to Saturday), when God rested from , made the day following Sabbath the first day of the week (corresponding to Sunday). Seventh-day Sabbaths were sanctified for celebration and rest. After the week was adopted in early Christianity, Sunday remained the first day
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