205 ILCS 5/19.1

As used in Sections 20 through 30 both inclusive of this Act and for purposes of any Section of the Illinois Bank Holding Company Act of 1957, the existence of a bank converted from a State bank to a national bank or vice versa, or from a trust company to a State bank, or from a State bank to an insured savings association or vice versa shall be measured from the date of the charter of the original entity.