Determination of the day of the week in the year row (07) is located in column G. The letter in the century row (13) and column G is E, so the day of the week is Friday. January 1 corresponds to G, G in the year row (00) corresponds to F in the century row (20), and F corresponds to Saturday. A pithy formula for the method: ""Date letter (G), letter (G) is in year row (00) for the letter (F) in century row (20), and for the day, the letter (F) become weekday (Saturday)"". Use 17 (in the Gregorian century row, column C) and 83 (in
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: