New theory links Dead Sea Scrolls' 364-day calendar to early use and later abandonment
Tel Aviv University scholar Eshbal Ratzon proposes the Qumran sect actively used its 364-day calendar in its formative centuries, yielding 52 weeks and shaping its break with Jerusalem; over time the system drifted from the solar year and changing Hasmonean politics under Alexander Jannaeus made practical use untenable, leaving the calendar as a religious ideal central to Qumran writings and the Book of Jubilees.