Just one method can get remote DB time

SQL> create or replace function test_remote_sysdate
  2  return date
  3  as
  4     l_cursor    int;
  5     l_status    int;
  6     l_remote_sysdate date;
  7  begin
  8
  9      l_cursor := dbms_sql.open_cursor@fcdw1cn;
10
11      dbms_sql.parse@fcdw1cn
12          ( l_cursor,
13            'begin :x := sysdate; end;',
14            dbms_sql.native
15          );
16
17      dbms_sql.bind_variable@fcdw1cn
18         ( l_cursor, ':x', l_remote_sysdate );
19
20      l_status := dbms_sql.execute@fcdw1cn
21         ( l_cursor );
22
23      dbms_sql.variable_value@fcdw1cn
24         (l_cursor, ':x', l_remote_sysdate );
25
26      dbms_sql.close_cursor@fcdw1cn
27         (l_cursor);
28
29      return l_remote_sysdate;
30  end;
31  /

Function created.

SQL>  select TO_CHAR(SYSDATE,'YYYYMMDD HH24:MI:SS'), TO_CHAR(test_remote_sysdate,'YYYYMMDD HH24:MI:SS') from dual;

TO_CHAR(SYSDATE,' TO_CHAR(TEST_REMO
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20080419 11:51:40 20080419 12:07:52