SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function dateDiff (children 1)
     ExpressionList (children 4)
      Literal \'day\'
      Function materialize (children 1)
       ExpressionList (children 1)
        Function toDate32 (children 1)
         ExpressionList (children 2)
          Literal \'2015-08-18\'
          Literal \'UTC\'
      Function toDate (children 1)
       ExpressionList (children 2)
        Literal \'2015-08-19\'
        Literal \'UTC\'
      Literal \'UTC\'
