Much of the Book of Mormon's chronology is based on the number of years which passed from the time Lehi left Jerusalem, which the is typically dated to "about 600 BC." A number of scholars have proposed more specific dates Lehi's departure, ranging from 605 BC-588 BC. Each proposed date has it's own strengths and weaknesses, and provides a slightly different context to consider for the background of the opening events in the Book of Mormon. Read at bit.ly/know475