how to insert current date and time in sql code example

Example 1: insert date sql

INSERT INTO FOO (xpto) VALUES(TO_DATE('17/12/2015', 'DD/MM/YYYY'));

Example 2: insert current date sql

INSERT INTO my_table (last_updated) VALUES(NOW());
INSERT INTO my_table (last_updated) VALUES(sysdate);	-- Oracle
INSERT INTO my_table (last_updated) VALUES(getdate());	-- SQL Server