Determination of the day of the week ISO 8601. The day designated with 7 may also be counted as "0", by applying the arithmetic modulo 7, which calculates the remainder of a number after division by 7. Thus, the number 7 is treated as 0, 8 as 1, 9 as 2, 18 as 4 and so on. If Sunday is counted as day 1, then 7 days later (i.e. day 8) is also a Sunday, and day 18 is the same as day 4, which is a Wednesday since this falls three days after Sunday. The basic approach of nearly all of the methods to calculate the
German Unity Day the first Prussian coronation of the king, which should not fall into the shadow of a united German holiday." On 31 July 1919, the Weimar Constitution would be accepted in its form by the Weimar National Congress. In memorial of this "Hour of birth of democracy", the 11 August was created as Constitution Day, because the President of the Empire, Friedrich Ebert, signed the constitution on this day. Shortly after the Nazis took power in 1933 (the so-called "Machtergreifung"), May Day (1 May) was established as a national holiday in the "German Reich". It was already celebrated as a "Day