Hi,
The ASA only keeps track of the concurrent connections. Mostlikely and http connection will last no more than 1 minute to display a webpage, imagine how many connections on an enterprise are per day?? Thats a lot.
Cisco ASA only counts the concurrent connections and does not keep track of the connections that happened days ago. If you want, you can use a reporting tool such as netflow collector. That way (depending on the netflow sever application) you can run reports and keep all that information for accounting purposes.
By itself, the ASA does not have a database of the connections that have been established, only the current ones. Again, if what you are looking is something to check the connections across the device at any given time, Ill suggest you to get a Netflow server.
Hope it helps.
Mike
Mike