There is no curfew for a person who is 17 or older in the state of Illinois. The Illinois Child Curfew Act applies to people who are less than 17 years of age.
The curfew act states that any person under the age of 17 cannot be at any public assembly, building, place, street or highway between 12:01 a.m. and 6:00 a.m. on Saturday and Sunday or between 11:00 p.m. and 6:00 a.m. the following day from Sunday to Thursday inclusive. Curfew hours start earlier for minors ages 12 to 16 and even earlier for minors under the age of 12.
A violation of the Child Curfew Act is a petty offense and it is punishable by fines. Minors and their parents or guardians can be charged with violating curfew laws.