Thursday "xoves" and Romanian "joi". This is also reflected in the p-Celtic Welsh "dydd Iau". The astrological and astronomical sign of the planet Jupiter (♃) is sometimes used to represent Thursday. Since the Roman god Jupiter was identified with Thunor (Norse Thor in northern Europe), most Germanic languages name the day after this god: "Torsdag" in Danish, Norwegian, and Swedish, "Hósdagur"/"Tórsdagur" in Faroese, "Donnerstag" in German or "Donderdag" in Dutch. Finnish and Northern Sami, both non-Germanic (Uralic) languages, uses the borrowing "Torstai" and "Duorastat". In the extinct Polabian Slavic language, it was "perundan", Perun being the Slavic equivalent of Thor. There
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,