The General Assembly shall provide by law for a uniform
effective date for laws passed prior to June 1 of a calendar
year. The General Assembly may provide for a different
effective date in any law passed prior to June 1. A bill
passed after May 31 shall not become effective prior to June
1 of the next calendar year unless the General Assembly by
the vote of three-fifths of the members elected to each house
provides for an earlier effective date.
Structure Illinois constitution