TO_DATE in PLSQL

Example 1:

TO_DATE('2020-10-29-11.40.15', 'YYYY-MM-DD-HH24.MI.SS', 'NLS_CALENDAR=GREGORIAN');

Example 2:

SELECT to_char(to_date('03-MAY-30','DD-Month-YY','NLS_CALENDAR=GREGORIAN'), 'YYYY-MM-DD') FROM dual;

Example 3:

new_head_rec_.delivery_date := TO_DATE(EXTRACT(DAY        FROM new_head_rec_.delivery_date) || '.' || 
                                       EXTRACT(MONTH FROM new_head_rec_.delivery_date)      || '.' || 
                                       EXTRACT(YEAR      FROM new_head_rec_.delivery_date)  || ' 00:00:00', 'dd.mm.yyyy HH24:MI:SS', 'NLS_CALENDAR=GREGORIAN');

Related Links:

Oracle / PLSQL: TO_DATE Function

SYSTIMESTAMP