How to call Chicago in United States from United States:
1 - Exit code when making an international call from United States
1 + (224 or 312 or 630 or 708 or 773 or 847 or 872) + Local Number - International dialing code format
Note: United States and United States are both members of NANP (North American Numbering Plan) so when calling between these countries, 1 is used in place of the country exit code.
World time zone information: