Oracle primeiro dia do ano passado
-- Oracle: First day of previous year
SELECT trunc(add_months(sysdate, -12), 'YEAR') FROM DUAL;
VasteMonde
-- Oracle: First day of previous year
SELECT trunc(add_months(sysdate, -12), 'YEAR') FROM DUAL;-- Last day of current month
SELECT trim(to_date(last_day(sysdate), 'DD/MM/YYYY')) AS LASTDAY FROM DUAL;