Final answer:
In law, if an offer's expiration time is not stated, it expires within a reasonable time, which depends on the context. For lease agreements, notice of termination often requires a 30-day notice. Resolutions may expire based on specific conditions being met, like actions by international bodies or legislative acts.
Step-by-step explanation:
If the time for the offer to expire is not stated, it will expire in a reasonable time under the circumstances. In the context of contract law, a reasonable time takes into account various factors such as the nature of the offer, market conditions, and the types of goods or services involved. For instance, an offer related to the sale of perishable goods might have a shorter reasonable time frame due to the risk of the goods spoiling, as opposed to an offer related to real estate, which might last longer due to the complex nature of property transactions.
By lease agreements, as exemplified by the given scenario, a tenant or property owner typically must give notice before termination of the lease after the initial period has expired, which is often set at 30 days. This allows both parties to adequately prepare for the change, be it through searching for new tenants or finding other living arrangements. Additionally, when laws require "just cause" for termination, the reason must be provided in the termination notice.
Similarly, resolutions such as governmental or corporate decrees may stipulate that they expire when certain conditions are met, such as the restoration of peace and security, or they may be terminated by an official act, such as a resolution of Congress. The principle of a reasonable time applies generally across various legal and contractual contexts as a means to ensure fairness when explicit durations are not provided.