Computer science education cannot make anybody an expert programmer any more than studying brushes and pigment can make somebody an expert painter. Eric S. Raymond
The DUAL table is a special one-row, one-column table present by default in Oracle and other database installations. The sysdate returns the current date from the oracle database server.
SELECT sysdate from dual;
The to_char funcation format the date.
SELECT TO_CHAR(SYSDATE, 'MM-DD-YYYY HH24:MI:SS') "NOW" FROM DUAL;