Alaska and Hawaii hold the two US zones that sit beyond the mainland. Alaska runs at UTC−09:00 as AKST and shifts for daylight saving; Hawaii sits at UTC−10:00 as HST and never moves. That difference means the gap between them changes by an hour twice a year.
One zone for nearly all of Alaska
Despite its size, almost all of Alaska keeps a single clock, one hour behind Pacific time. Only the far western Aleutians use Hawaii–Aleutian time. The arrangement is deliberately practical: a geographically honest set of zones would have split the state four ways.
Hawaii never changes
Hawaii's tropical latitude means daylight barely varies across the year, so daylight saving would achieve nothing. In summer Hawaii runs three hours behind Pacific time; in winter, two. More in time in US territories.