Simplify the following text for a Grade 7 native English-speaking person.
Original: Liber AL vel Legis contains three chapters , each of which was written down in one hour , beginning at noon , on 8 April , 9 April , and 10 April .
Simplified: It contains three chapters , each of which was written down in one hour , beginning at noon , on April 8 , April 9 , and April 10 .