3.5  Failure of governor to return bill.
  When a bill has passed the general assembly, and is not returned by the governor within three days as provided in the Constitution, it shall be authenticated by the secretary of state endorsing thereon:
  This bill, having remained with the governor three days (Sunday excepted), the general assembly being in session, has become a law this ............ day of ................................, ............

....................................,

Secretary of State.
[C51, §18; R60, §21; C73, §30; C97, §33; C24, 27, 31, 35, 39, §51; C46, 50, 54, 58, 62, 66, 71, 73, 75, 77, 79, 81, §3.5]
Iowa Constitution, Art. III, §16