Listing periods are negotiable but 180 days is standard. Sometimes I will agree to shorter but it depends upon the situation. If I think the price the seller wants to ask is high I am more likely to require the full 180 days. I often invest alot of money upfront to sell a home and want time to prove to the seller we have tested the market. It takes time to get some sellers to realize that the only wrong is the price. I am not saying this is the case here.