HRS §490:2-309
What happens when a contract has no set time or end date
If a contract does not say when something must happen, it must happen within a reasonable time. If a contract has no end date but involves repeated actions, it lasts for a reasonable time and either side can end it with reasonable notice. Ending a contract requires giving the other side reasonable notice, and you cannot agree to skip notice if that would be unfair.
everyone
The statute, as written — Absence of specific time provisions; notice of termination
(1) The time for shipment or delivery or any other action under a contract if not provided in this article or agreed upon shall be a reasonable time. (2) Where the contract provides for successive performances but is indefinite in duration it is valid for a reasonable time but unless otherwise agreed may be terminated at any time by either party. (3) Termination of a contract by one party except on the happening of an agreed event requires that reasonable notification be received by the other party and an agreement dispensing with notification is invalid if its operation would be unconscionable.
LawTrove is not legal advice. The summary above is a computer-generated restatement — the authoritative text is the official version linked above.