When did Satan fall?

At the end of the six day creation, God called His creation, “very good”. Satan was still an angel at this time. Corinthians tells us that death is an enemy to God’s creation. The creation was certainly not full of death at the end of the sixth day and Romans tells us that death came due to man’s original sin. This sin separated us from God and required a Redeemer to reunite us with God. That Redeemer is the Lord Jesus Christ. Death before sin would eliminate any need for Jesus. Ezekiel 28:13-15 tells us that Satan walked in the garden, created on day six, till iniquity was found in him. This was sometime between day seven and one hundred years later. We can surmise this due to Adam being booted from the garden prior to the births of Cain and Able, and the birth of Seth when Adam was 130 years old. This destroys the Gap Theory, Day Age Theories, Progressive Creation, pre-Adamite men, death before sin, etc.