In a commercial real estate purchase context, a fixed period of time during which a purchaser (or investor) has an opportunity to review and evaluate information and materials relative to the property. During the due diligence period, the purchaser (or investor) can verify the property meets its investment expectations and intended use of the property. Due diligence periods are negotiable between the parties and the amount of time varies depending on the specific details of each transaction, the market, and the parties' negotiating leverage.