Unless there is a set time frame in the contract, then there is not a time frame. However, the buyer has the right to withdraw the offer which could leave the seller without a contract at all. In this market it would seem that you would not want lose a buyer for an unknown offer, that may or may not come in. The seller maybe deciding if they can live with the offer, or if they can line up a moving company to accomodate the settlement date etc. I dont think it is unreasonable for the seller to take a day or so from when it was presented if needed. I would talk to the listing agent, find out the time frame is and let the buyers decide if it is worth waiting for or if they want to withdraw. You did not mention how long you have been waiting for a response.