Sat and 26 is in column Fri, so the day name for the date is Wed located in row Sat and column Fri. 93 (year mod 100) is in row Thu (year row) and the day name Wed in the year row is located in column Sun. 18 ([year/100] in the Gregorian century column) is in row Wed (century row) and the day name in the century row and column Sun is Tue, so the day of the week is Tuesday.