How long was it from Abraham's call until Joshua led Israel into the land?

Les teaches that for four hundred and almost ninety years, from Abraham's call until Joshua led Israel into the land, God was waiting for the Canaanites to turn from their iniquity. Instead, they went deeper and deeper into wickedness, immorality, and abominations. Finally, God told Joshua not to spare any of them, because their rottenness would infect Israel. Les illustrates this with a container of good potatoes or apples: if you put a half-rotten one in the middle, it won't be long until the whole group is rotten. God was teaching Israel that they had to remove the rot, or it would infect and destroy them.