364 Day Calendar. It has four quarters of 13 weeks and 91 days. Ratson described the calendar as “perfect” since 364 divides into 7 allowing every date to fall on a specific day of the week and giving every holiday a fixed date.
Instead of a day every four years, this calendar adds a leap week every five to six years. Thus, the current state of understanding is that the qumran calendar has a year of 364 days comprising 12 months of 30 or 31 days each and has holy days occurring every year on known fixed days.