What are the instances when a bill becomes a law?

1. APPROVED AND SIGNED by the PRESIDENT 2. Presidential veto OVERRIDDEN BY 2/3 VOTE of all members of both Houses 3. FAILURE OF THE PRESIDENT TO VETO the bill and to return it with his objections to the House where it originated, within 30 days after the date of receipt 4. A bill calling a SPECIAL ELECTION for President and Vice-President under Sec. 10. Art. VII becomes a law upon its approval on the third reading and final reading.