Eugen Mittwoch behalf of Mittwoch. Because of their colonial activities in Ethiopia, the Italians were extremely interested in Mittwoch's knowledge and research. Mittwoch was very active on behalf of the Ethiopian Jews (Falasha), and was also one of the first German Jews who could speak fluent Ivrit. Starting in 1933, Mittwoch used his "privileged" position in Germany (he continued to receive his salary as a German professor until the beginning of the war) on behalf of the Jewish community, he became head of the American Jewish Joint Distribution Committee in Berlin. However, in 1938, after Kristallnacht, also Mittwoch had to emigrate, and
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,