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 in the respective annual celebration to represent the modern borders of Germany. German Unity Day The Day of German Unity () is the national day of Germany, celebrated on 3 October as a public holiday. It commemorates the anniversary of German reunification in 1990 when the goal of a united Germany, that originated in the middle of the 19th century, was fulfilled (with the exception of Austria and the German cantons in Switzerland). Therefore, the name addresses neither the re-union nor the union, but the unity of Germany. The Day of German Unity on 3 October has been the German