Assuming it was federal minimum wage of $7.25/hr and he was working 60 hour weeks with 20 hours of time and a half pay at $10.875 it would take exactly 9,149,826 years working 3120 hours a year for a total of 28,547,457,120 hours worked. Or if satan is nice and lets him have more time off and jeff only has to work 40 hours a week then he will have to work 15,994,695 years or a total of 33,268,965,600 hours. If only hell were real so billionaires could be adequately punished.
Your calculations are gross income. He should also have to pay Satan his tax, as well as pay for food and housing. With all that, he would have very little saved and take much longer.