Names of the days of the week is followed by a number indicating the day: "Monday" is literally "star day one", "Tuesday" is "star day two", etc. The exception is Sunday, where rì (日), meaning "sun" or "day", is used instead of a number. In Swahili, the day begins at sunrise, unlike in the Arabic and Hebrew calendars where the day starts at sunset (therefore an offset of twelve hours), and unlike in the Western world where the day starts at midnight (therefore an offset of six hours). Saturday is therefore the first day of the week, as it is the day that includes the first night
Determination of the day of the week January 1, 2000. (year − 1 for January) formula_3 formula_4 Note: The first is only for a 00 leap year and the second is for any 00 years. The term mod 7 gives the values of months: The term mod 7 gives the values of years: The term mod 7 gives the values of centuries: Now from the general formula: formula_5; January 1, 2000 can be recalculated as follows: formula_6 formula_7 Kraitchik proposed two methods for calculating the day of the week. One is a graphical method. The other uses a formula that he credits to Gauss on p. 110: