Located in the Eastern (GMT -05:00) time zone. Area code 410 serves the state of Maryland. This area code was assigned on December 28th, 1990. On October 6th, 1991 it went into service. 410 is a General Purpose Code. 410 service area does overlap with 443 667 area codes. Dialing pattern for local calls within the same NPA (area code) is 10D.