How much notice do I have to give my employer before taking time off?
Generally, you must give your employer "reasonable notice" that you plan to take time off from work to deal with a situation involving domestic or sexual violence to you or your child.1 For example, if you find out on a Tuesday that you have to go to court on Friday afternoon to testify against your abuser, you should tell your employer on Tuesday, or as soon as possible, that you will need Friday off -- don't wait until Friday morning.
However, there is an exception to the "reasonable notice" requirement if it is not possible to give notice to your employer due to immediate or sudden danger to yourself or your minor child.1
Note: It might be a good idea to ask your employer in writing for the time off to deal with domestic or sexual violence issues and to keep a copy of the letter. This way, if the employer denies you the time off, you have some proof that you asked for it in case you decide to bring legal action against the employer for violating the law.
1 H.R.S. § 378-72(f)