14 Ill. Adm. Code 135.2101
Computation of Time
Section 135
Section 135.2101Â Computation
of Time
The time within which an act
under the Act shall be done shall be computed by excluding the first day and
including the last, unless the last day is a Saturday, Sunday or holiday as
defined or fixed in any statute now or hereafter in force in this State, and
then it shall also be excluded. If the day succeeding such Saturday, Sunday or
holiday is also a Saturday, Sunday or holiday, then such succeeding day shall
also be excluded.