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
Week called an octave, particularly in Roman Catholic liturgy. In German, the phrase "in acht Tagen" (literally "in eight days") means one week from today. In Italian, the phrase ("oggi otto" (literally "today eight") also means one week from today. Weeks in a Gregorian calendar year can be numbered for each year. This style of numbering is commonly used (for example, by schools and businesses) in some European and Asian countries, but rare elsewhere. ISO 8601 includes the ISO week date system, a numbering system for weeks – each week begins on a Monday and is associated with the year that