Constitution of the State of Indiana Art. 4, § 9

Section 9. The sessions of the General Assembly shall be held at the capitol of the State, commencing on the Tuesday next after the second Monday in January of each year in which the General Assembly meets unless a different day or place shall have been appointed by law.  But if, in the opinion of the Governor, the public welfare shall require it, he may, at any time by proclamation, call a special session.  The length and frequency of the sessions of the General Assembly shall be fixed by law.