select sysdate-to_yminterval('1-0') from dual
select sysdate-1/24 from dual;
select ( (sysdate-1/24) - (sysdate-to_dsinterval('0 02:30:00')) ) day to second from dual;
alle angestellten die länger als 12 Jahre "dabei" sind
select last_name, hire_date, (sysdate - hire_date) year to month as dauer
from employees where hire_date + to_yminterval('12-0') < sysdate
order by hire_date desc
select last_day(last_day(sysdate)+1 - to_yminterval('0-2')) from dual;
select ADD_MONTHS(sysdate+1, -1) from dual