Final answer:
There is no specific time frame mandated by the U.S. Constitution for filling a Senate vacancy, but the governor must call a special election promptly. The governor may also make a temporary appointment if permitted by state legislature, lasting until a special election is held.
Step-by-step explanation:
When a vacancy occurs on the Board, commonly referring to the Senate based on the context provided, there is no fixed time frame mandated by the Constitution for the seat to be filled. However, according to Section 2 Clause 4 and the 17th Amendment, the executive authority of the state, which is usually the governor, must call a special election to fill the vacancy. This must be done 'when vacancies happen,' indicating that action should be taken promptly.
The process may also vary depending on whether the state legislature allows for temporary appointments. If such an appointment is permitted, the governor can fill the vacancy temporarily until the special election occurs. The length of time before the special election is held can vary based on state laws and the date of the next scheduled election.
In some cases, the Constitution allows the President to fill vacancies during the Senate's recess, but these appointments expire at the end of the Senate's next session. It's important to note that the specifics can change based on individual state laws, as they might have different procedures for handling vacancies and special elections.