Get Start and end date of Week according to string

I want to display the start date and end date of the week. I have One date and a string like 1W4 and,in 1W4 consider 4 weeks and 1 visit so, my string like this 2W4,1W2,3W3,1W1,2W4.

I want to make start date and end date of week array according to string and week start from Sunday to Saturday.

Please post me if anyone has solution.Please ignoring if mistake in asking Question.

Thank you.

via Chebli Mohamed