G4521:
σάββατον
(sábbaton)
of Hebrew origin (שַׁבָּת); the Sabbath (i.e. Shabbath), or day of weekly repose from secular avocations (also the observance or institution itself); by extension, a se'nnight, i.e. the interval between two Sabbaths; likewise the plural in all the above applications:--sabbath (day), week.