Zal Answers the Mobadan's Riddles

From A8.19, Zal Answers the Mobadan. It illustrates A8.19.1–7:

A8.19.1
Zal paused a while, absorbed in inward thought,And weighed each hidden question they had brought.
A8.19.2
He raised his mane and spread his shoulders wide,Then every hidden answer he supplied:
A8.19.3
“The cypresses, those twelve tall trees you named,Are months by which the passing year is framed.
A8.19.4
Each bears full thirty branches in its span,The days that mark the measure dealt to man.
A8.19.5
When thirty days are passed, their course is done;Thus turns the wheel beneath the circling sun.
A8.19.6
You spoke of chargers, one in white, one black,That chase each other, never tired nor slack.
A8.19.7
These are the two that sweep across the sky:The night and day that ever onward fly.