It works just like an open bar at a reception – they can come up to the cart and order what they want as many times as they want throughout the serving period. We serve between 2-3 hours, depending on the size of the party. As a general rule, a party or event with 75-125 people will serve for 2 hours. A party with 125-200 will generally serve your requests for 2.5 – 3 hours.