In the event that there would be no built-in adjustments made in the Jewish calendar, the holiday of Pesach would slip back one solar month every three years.
(no built-in adjustments; made; L:in the Jewish calendar) (the holiday of Pesach; would slip; back; T:one solar month every three years)
no built-in adjustments the holiday of Pesach
made would slip
L:in the Jewish calendar
back T:one solar month every three years