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 since the start of the century, and then add these together along with the number of years since the start of the century, and the day number of the month. Eventually, one ends up with a day-count to which one applies modulo 7 to determine the day of the week of the date. Some methods do all the additions first and then cast out sevens, whereas others cast them out at each step, as in Lewis Carroll's method. Either way is quite viable: the former is easier for calculators and computer programs; the latter for mental calculation (it is quite