Iowa Constitution Art. III, § 26. Time laws to take effect

An act of the general assembly passed at a regular session of a general assembly shall take effect on July 1 following its passage unless a different effective date is stated in an act of the general assembly. An act passed at a special session of a general assembly shall take effect ninety days after adjournment of the special session unless a different effective date is stated in an act of the general assembly. The general assembly may establish by law a procedure for giving notice of the contents of acts of immediate importance which become law.