Calculating time difference

SQL> SELECT to_number( to_char(to_date('1','J') +
2 (date1 - date2), 'J') - 1) days,
3 to_char(to_date('00:00:00','HH24:MI:SS') +
4 (date1 - date2), 'HH24:MI:SS') time
5 FROM dates;

DAYS TIME
---------- --------
1 00:00:00
0 01:00:00
0 00:01:00