Each month (a word derived from moon) was either 29 or 30 days to correspond to the 29.5 days it takes the moon to orbit the earth.
(a word; derived; from moon) (Each month; was; either 29 or 30 days to correspond to the 29.5 days) (either 29 or 30 days; to correspond; to the 29.5 days)
a word Each month either 29 or 30 days
derived was to correspond
from moon
either 29 or 30 days to correspond to the 29.5 days
to the 29.5 days