Patent ID: 7321863

Claim:
A method for providing product availability information to a user from at least one product source, where a product has one or more associated different start dates indicating when a user may initiate use of the product, said method comprising: accessing at least one product source and requesting product availability information concerning at least one product prior to receipt of a product availability request from a user concerning the product; storing the product availability information received from the product source in a storage device; receiving a product availability request from the user concerning a requested product; accessing the product availability information stored in the storage device for the requested product; determining the availability of the requested product based on at least the product availability information stored in the storage device; generating an availability response based on at least the product availability information stored in the storage device; and updating the product availability information stored in the storage device more often for start dates of the requested product that occur sooner in time than for start dates that occur later in time, wherein the requested product can be used beginning on a particular start date and may be used for different lengths of use from the start date; wherein said storing step comprises storing product availability information including start dates and a maximum length of use for each start date; wherein said receiving step comprises receiving an availability request from the user concerning the requested product, a requested start date and a requested length of use; wherein said determining step comprises determining the availability of the requested product for the requested start date and the requested length of use from the product availability information stored in the storage device; and wherein when the requested length of use for the requested product exceeds the maximum length of use stored in the storage device, said determining step comprises: dividing the requested length of use into at least two selected lengths of use that are each less than the maximum length of use stored in the storage device, each selected length of use having an associated selected start date; and determining the availability of the requested product for each selected start date and selected length of use to determine the availability of the product for the requested start date and requested length of use.