Ind. Code § 1-1-3.1-3
(b) If the act provides that a provision of the act takes effect:
(2) retroactively to a specified date;
then the provision takes effect upon approval of the act.
(c) If:
(2) approval of the act occurs on or before the specified date;
then the provision takes effect on the specified effective date.
(d) If:
(2) approval of the act occurs after the specified date;
then the provision takes effect on July 1 next following approval of the act.
As added by P.L.1-1987, SEC.2.