HST to PST

Hawaii Standard Time is UTC−10 all year. When the Uniform Time Act of 1966 let states opt out of daylight saving, Hawaii did so in 1967: close to the tropics, its days are long all year and sunrise barely moves between seasons, so shifting the clock would add little evening light. California switches between PST (UTC−8) and PDT (UTC−7) on the second Sunday of March and the first Sunday of November, which is why the gap is 2 hours in winter and 3 in summer.

HST is shared with the Aleutian Islands of Alaska, but the Aleutians do observe daylight saving and move to HDT in summer. On UltKit, HST always means Honolulu.

Flights from Honolulu to Los Angeles take about five hours eastbound, and the time difference makes them feel longer. A red-eye leaving Honolulu at 10:00 PM lands around 5:00 AM in Los Angeles in winter and 6:00 AM in summer, so you lose a night's sleep plus two or three hours on the clock. Visitors from the US West Coast are Hawaii's largest tourism market, and airlines run dozens of daily flights between the islands and California.

For working together, the overlap is generous. A Honolulu workday from 8:00 AM to 3:00 PM covers 10:00 AM to 5:00 PM in California in winter; in summer, Honolulu's 8:00 AM to 2:00 PM matches California's 11:00 AM to 5:00 PM. Mainland deadlines at 5:00 PM Pacific fall at 3:00 or 2:00 PM in Hawaii. The California to Hawaii page has the reverse view, and Hawaii to New York covers the East Coast.