When was the book of Exodus written?
The book of Exodus preserves the truth about the scribe’s familiarity about Egyptian calendar by mentioning the feast of Ingathering in year end using Egyptian based on the seasonal cycles of river Nile while the other books in the law mentions it as feast of Tabernacles in seventh month using the calendar given by God based on the seasons in ancient Israel. This means, the earliest content written in the book of Exodus must be as old as 1468 BC.