Answer should be 100% correct with logic.

WHAT IS THE DUE DATE? 1: Tenor is at 3 months after sight,the accepting date is October 1st, 2020, so the due date is? 2: Tenor is at one month after 31th Jan, 2020, so the due date is? 3: Tenor is "at 3 and a half months after 15th Feb, 2020, so the due date is? 4: Tenor is at 15 days from 21st May, 2020. so the due date is