When the time is 18:00 GMT, it is noon in the eastern United States, 11 a.m. in the central United States, 10 a.m. in the mountains, 9 a.m. along the Pacific, 8 a.m. in Alaska and 6 a.m. in Hawaii. The time 18:00 GMT is the same as 6 p.m.
GMT stands for Greenwich Mean Time. The four continental time zones that cover the United States are Eastern Standard Time, Central Standard Time, Mountain Daylight Time and Pacific Daylight Time. The time zone for most of Alaska is AKDT, short for Alaska Daylight Time. The time zone for Hawaii is HAST, short for Hawaii-Aleutian Standard Time.