35 ILCS 200/14-35
In counties with 3,000,000 or more inhabitants, the county assessor each year shall sit for the purpose of revising the assessments. The time of the sittings shall be set by the county assessor by notice as herein provided after the assessment books for one or more townships or taxing districts have been completed. The assessments for one or more townships or taxing districts may be revised at any sitting which may be adjourned from day to day as necessary. At least one week before each sitting the county assessor shall publish a notice, in some newspaper of general circulation published in the county, of the time and place of the sitting, the township or townships, taxing district or taxing districts for which the assessments will be considered at the sitting, and the time within which applications for revisions of assessment may be made by taxpayers. The county assessor shall, upon completion of the revision of assessments for any township or taxing district, deliver the assessment books for the township or taxing district to the board of appeals (until the first Monday in December 1998 and the board of review beginning on the first Monday in December 1998 and thereafter).
35 ILCS 200/14-35