SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 1)
   ExpressionList (children 1)
    Function age (children 1)
     ExpressionList (children 3)
      Literal \'day\'
      Function toDate (children 1)
       ExpressionList (children 2)
        Literal \'2015-08-18\'
        Literal \'UTC\'
      Function materialize (children 1)
       ExpressionList (children 1)
        Function toDateTime64 (children 1)
         ExpressionList (children 3)
          Literal \'2015-08-19 00:00:00\'
          Literal UInt64_3
          Literal \'UTC\'