Illinois Summons — Certain Day is a legal document used in Illinois courts to initiate a civil lawsuit or other legal action. It is issued by the court and served on the defendant to inform them of the lawsuit and their obligation to appear in court on a certain day. The Summons includes the name of the court, the caption of the lawsuit, the date of the first hearing, and the amount of time the defendant has to respond to the complaint. There are two types of Illinois Summons — Certain Day: a Summons to Appear, which requires the defendant to appear in court at a specified time and date; and a Summons to Answer, which requires the defendant to respond to the complaint in writing.