1o_ In group of seven . It is a syncopation of the Latin septimana ("of the seventh" ). 2nd_ Period of seven consecutive days in principle already established according to culture or custom, for example from Monday to Sunday (civil week, according to ISO-8601 ), or from Sunday to Saturday (by Catholic influence) ; although it is also used as "seven days from. . . " designating any one as a start. See Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday.