50 Ill. Adm. Code 2402.60
Computation of Time
Section 2402
Section 2402.60 Computation
of Time
a) Computation of any period of time prescribed by this rule
shall begin with the first business day following the day on which the act,
event or development initiating such period of time occurs, and shall run until
the end of the last day, or the next following business day if the last day is
a Saturday, Sunday, or legal holiday. Where the period of time is five days or
less, Saturdays, Sundays and legal holidays shall be excluded in the
computation of time.
b) Notice requirements shall be construed to mean notice received
but proof that notice was dispatched by means reasonably calculated to be
received by the prescribed date shall be prima facie proof that notice was
timely received.