Located in the Eastern (GMT -05:00) time zone. Area code 973 serves the state of New Jersey. This area code was assigned on January 23rd, 1997. On June 1st, 1997 it went into service. 973 is a General Purpose Code. 973 service area does overlap with 862 area codes. Dialing pattern for local calls within the same NPA (area code) is 10D. Calls between the 973 and 862 NPAs can be dialed as 10D.