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