Names of the days of the week which is mainly based on a medieval version of Spanish, the five days of Monday–Friday closely follow the Spanish names. Sunday uses the Arabic name, which is based on numbering, because a Jewish language was not likely to adapt a name based on "Lord's Day" for Sunday. As in Spanish, the Ladino name for Saturday is based on "Sabbath". However, as a Jewish language—and with Saturday being the actual day of rest in the Jewish community—Ladino directly adapted the Hebrew name, "Shabbat". From Latin "Dominicus (Dominica)" or Greek Κυριακή (Christian Sabbath) After No Work. In Russian also "Day After Week(end)"
Determination of the day of the week his collected works in 1927. Gauss' method was applicable to the Gregorian calendar. He numbered the weekdays from 0 to 6 starting with Sunday. He defined the following operation: The weekday of 1 January in year number is where is the remainder after division of by , or modulo . This formula was also converted into graphical and tabular methods for calculating any day of the week by Kraitchik and Schwerdtfeger. Another variation of the above algorithm likewise works with no lookup tables. A slight disadvantage is the unusual month and year counting convention. The formula is where For example,