Haw. Rev. Stat. § 302A-1140: Religious holy days.

The board shall release any public school student from school attendance for the purpose of observing religious holy days that fall on regularly scheduled school days, when the release is requested in writing by a parent, guardian, or other person having custody or control of the pupil. Actual attendance at observances shall count as an excused absence at the public schools for all purposes where attendance forms the basis of computation.