Michael has a credit card with an APR of 15.33%. It computes finance charges using the daily balance method and a 30-day billing cycle. On April 1st, Michael had a balance of $822.05. Sometime in April, he made a purchase of $77.19. This was the only purchase he made on this card in April, and he made no payments. If Michael’s finance charge for April was $10.71, on which day did he make the purchase?