MLS Rule 2.5 states status changes are to be made within 3 days. MLS Rule 1.4 also designates a within 3 days period of time for price and status changes. Members found in violation of the MLS Rules are subject to disciplinary action including fines. The complete MLS Rules, including the Top Rules To Remember, are readily available to members under the MLS tab on their member dashboard.
It should be done in a timely manner. As soon as all parties have signed the contract and the contract is executed and receipted at the title company the status should be changed.