ICT is an Asian civil-time label, currently 7h ahead of UTC at +07:00. The lead reference is Ho Chi Minh City, and the wider grouping reaches 4 countries through 4 IANA zones.
The busiest cities using ICT in the current catalog are Ho Chi Minh City, Hanoi, Bangkok, Haiphong, and Phnom Penh. The lead live reference on this page is Ho Chi Minh City (Asia/Ho_Chi_Minh), currently at +07:00 (GMT+7). Those cities are what give ICT its actual feel rather than the abstract offset.
ICT has a local identity beyond its offset: mainland Southeast Asia through Thailand, Vietnam, Cambodia, and Laos. Calendar signals such as Songkran, Tet, Khmer New Year, and Pi Mai Lao and operational signals such as Bangkok tourism, Vietnam manufacturing, Cambodia and Laos government scheduling, and Mekong-region support handoffs are why this abbreviation should not be flattened into a same-offset neighbor.
ICT is stable on Asia/Ho_Chi_Minh year-round, with no seasonal clock changes in the next year. That makes it a low-friction choice for recurring meetings and broadcast schedules — but software still prefers the IANA zone because governments can change civil-time rules independently of the short code.