(n.) A period of seven days, usually that reckoned from one Sabbath or Sunday to the next.

Heptateuch abundant year academic year annum bissextile year calendar month calendar year century common year day decade decennary decennium defective year fiscal year fortnight heptachord heptad heptagon heptahedron heptameter heptarchy heptastich hour leap year lunar month lunar year lunation luster lustrum man-hour microsecond millennium millisecond minute moment month moon quarter quinquennium regular year second semester septennate septet septuor session seven sevener sidereal year solar year sun term trimester twelvemonth weekday year