Located in the Central (GMT -06:00) time zone. Area code 224 serves the state of Illinois. This area code was assigned on May 1st, 1998. On January 5th, 2002 it went into service. 224 is a General Purpose Code. 224 service area does overlap with 847 area codes. Dialing pattern for local calls within the same NPA (area code) is 1+10D.