Determination of the day of the week day of the week begins by starting from an ‘anchor date’: a known pair (such as January 1, 1800 as a Wednesday), determining the number of days between the known day and the day that you are trying to determine, and using arithmetic modulo 7 to find a new numerical day of the week. One standard approach is to look up (or calculate, using a known rule) the value of the first day of the week of a given century, look up (or calculate, using a method of congruence) an adjustment for the month, calculate the number of leap years
German-American Day German-American Day German-American Day () is a holiday in the United States, observed annually on October 6 under . German-American Day, which celebrates German American heritage, commemorates the date in 1683 when 13 German families from Krefeld, near the Rhine, landed in Philadelphia. These families subsequently founded Germantown, Pennsylvania, the first German settlement in the original thirteen American colonies, and organized the first petition in the English colonies to abolish slavery in 1688. Originally known under the rubric of "German Day", the holiday was celebrated for the first time in Philadelphia in 1883, on the occasion of the 200th anniversary