Haw. Rev. Stat. § 1-31: Hawaiian standard time; definition; observance.

Hawaiian standard time is ten hours slower than Greenwich time, based on the mean solar time of the one hundred and fiftieth degree of longitude west from Greenwich and shall be the time which the entire State, including all of its political subdivisions, shall observe annually, notwithstanding the daylight time conversion provisions of the Uniform Time Act of 1966, Public Law 89-387, 80 Statutes at Large 107.