The Jewish calendar is based on a lunar cycle (that is, each month is based on the interval, about 29 or 30 days, from new moon to new moon--so it's short by about 11 days per solar year.
(that; is; each month is based on the interval, about 29 or 30 days, from new moon to new moon) Context(that is,List([47, 54))):(each month; is based; on the interval, about 29 or 30 days, from new moon to new moon)
that is,List([47, 54))
that each month
is is based
each month is based on the interval, about 29 or 30 days, from new moon to new moon
on the interval, about 29 or 30 days, from new moon to new moon