Quick definitions from WordNet (Atlantic standard time)
▸ noun: standard time in the 4th time zone west of Greenwich, reckoned at the 60th meridian; used in Puerto Rico and the Virgin Islands and Bermuda and the Canadian Maritime Provinces
▸ noun: standard time in the 4th time zone west of Greenwich, reckoned at the 60th meridian; used in Puerto Rico and the Virgin Islands and Bermuda and the Canadian Maritime Provinces