25 ILCS 15/2
Upon the filing of a joint proclamation for a special session under Section 1, the Secretary of State shall, at least 4 days before the date set for the convening of that special session, send written notice by certified mail to each member of the General Assembly of the joint proclamation and the purpose, date, and time set for the convening of the special session. If the Speaker and President declare in the joint proclamation that a demonstrable emergency exists which requires immediate action by the General Assembly, the requirements of this section shall be suspended and the Secretary of State shall take whatever reasonable steps necessary to notify the members of the General Assembly of the date and time of the emergency special session.
25 ILCS 15/2