Located in the Eastern (GMT -05:00) time zone. Area code 220 serves the state of Ohio. This area code was assigned on December 11th, 2013. On April 22nd, 2015 it went into service. 220 is a General Purpose Code. 220 service area does overlap with 740 area codes. Dialing pattern for local calls within the same NPA (area code) is 10D. Carriers must provide permissive 1+10D dialing for Foreign NPA Local Calls in areas where they provide optional EAS.