Each of W, X, Y, Z. A, B and C has a wedding to attend on a different day of a week starting from Monday to Sunday of the same week. C has to attend wedding immediately after A. Y has to attend a wedding on one of the days before B and W. Only Z has to attend a wedding before A. X has to attend a wedding on Friday. B does not have to attend a wedding on Sunday. On which day of the week does Y have to attend a wedding?