SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function dateDiff (children 1)
     ExpressionList (children 4)
      Literal \'month\'
      Function toDate32 (children 1)
       ExpressionList (children 2)
        Literal \'2015-08-18\'
        Literal \'UTC\'
      Function toDateTime (children 1)
       ExpressionList (children 2)
        Literal \'2015-09-18 00:00:00\'
        Literal \'UTC\'
      Literal \'UTC\'