```
SQL> select to_timestamp('2010-12-14:09:56:53') - to_timestamp('2010-12-14:09:56:46') from dua
l;
select to_timestamp('2010-12-14:09:56:53') - to_timestamp('2010-12-14:09:56:46') from dual
                    *
ERROR at line 1:
ORA-01843: not a valid month

SQL> select to_date('2010-12-14:09:56:53') - to_date('2010-12-14:09:56:46') from dual;
select to_date('2010-12-14:09:56:53') - to_date('2010-12-14:09:56:46') from dual
               *
ERROR at line 1:
ORA-01861: literal does not match format string

```

What is the correct way to do a

```
2010-12-14:09:56:53
minus
2010-12-14:09:56:46

```

in Oracle SQL?