It’s actually illegal to use sparklers (considered as “consumer fireworks”) other than during authorized dates and times, i.e., New Year’s Eve and 4th of July.

“Consumer fireworks” means any fireworks designed primarily for retail sale to the public during authorized dates and times, that produces visible or audible effects by combustion, and that is designed to remain on or near the ground and, while stationary or spinning rapidly on or near the ground, emits smoke, a shower of colored sparks, whistling effects, flitter sparks, or balls of colored sparks, and includes combination items that contain one or more of these effects. “Consumer fireworks” shall comply with the construction, chemical composition, and labeling regulations of the United States Consumer Product Safety Commission as set forth in Title 16 Code of Federal Regulations and fireworks classified as UN0336 and UN0337 by the United States Department of Transportation as set forth in Title 49 Code of Federal Regulations. “Consumer fireworks” include firework items commonly known as firecrackers that are single paper cylinders not exceeding one and one-half inches in length excluding the fuse and one-quarter of an inch in diameter and contain a charge of not more than fifty milligrams of pyrotechnic composition, snakes, sparklers, fountains, and cylindrical or cone fountains that emit effects up to a height not greater than twelve feet above the ground, illuminating torches, bamboo cannons, whistles, toy smoke devices, wheels, and ground spinners that when ignited remain within a circle with a radius of twelve feet as measured from the point where the item was placed and ignited, novelty or trick items, combination items, and other fireworks of like construction that are designed to produce the same or similar effects.

Information found on http://www.capitol.hawaii.gov/hrscurrent/Vol03_Ch0121-0200D/HRS0132D/HRS_0132D-0002.htm