Who among the following person visited on 9 May?

We have: P visits on 12 of the month having 30 days. Three persons are visited between P and W, who neither visits along with D nor Y in the same month. That means, in case (1) P visited on 12 April, in case (2) P visited on June 12. X visits on 12th May and Y visits two persons before D, who neither visits in the same month along with W nor X. That means, in case (1) Y visited on 9 March, in case (2) Y visited on 9 May. Based on the above given information we have: Again, we have: One person visits between Q and C, who visits after Q. A visits after Y but before Q. That means, in case (1) Q visited on 9 May, case (2) is not valid. Based on the above given information we have: Case (2) is not valid as A visits after Y but before Q.