Determination of the day of the week the day of the week without any calculations. Examples: December is in row F and 26 is in column E, so the letter for the date is C located in row F and column E. 93 (year mod 100) is in row D (year row) and the letter C in the year row is located in column G. 18 ([year/100] in the Gregorian century column) is in row C (century row) and the letter in the century row and column G is B, so the day of the week is Tuesday. October 13 is a F day. The letter F
Week an early continuous use of a seven-day week; referring to the Jews during the Babylonian Captivity in the 6th century BC, after the destruction of the Temple of Solomon. While the seven-day week in Judaism is tied to Creation account in the Book of Genesis in the Hebrew Bible (where God creates the heavens and the earth in six days and rests on the seventh; , in the Book of Exodus, the fourth of the Ten Commandments is to rest on the seventh day, "Shabbat", which can be seen as implying a socially instituted seven-day week), it is not clear