35 ILCS 200/16-110
In counties with 3,000,000 or more inhabitants, at least one week before its meeting to revise and correct assessments, the board of appeals (until the first Monday in December 1998 and the board of review beginning the first Monday in December 1998 and thereafter) shall publish a notice of the time and place of that meeting. The board shall, from time to time, publish notices which shall specify the date and place at which complaints may be filed for those townships or taxing districts for which property assessments have been completed by the county assessor, and which will then be considered for revision and correction at that time. All notices required by this Section may provide for a revision and correction at the specified time of one or more townships or taxing districts. All such notices shall be published once in at least one newspaper of general circulation published in the county. The board at the time and place fixed, and upon notice as provided in this Section, may receive and hold hearings on all those complaints and revise and correct assessments within those townships or taxing districts. Taxpayers shall have at least 20 days after the date of publication of the notice within which to file complaints.
35 ILCS 200/16-110