US Patent 9460141 Automatic expiring of cached data

A method includes determining a time shift for data validity windows corresponding to a user, receiving a request for an incremental data update from the user, the user having cached data, determining that the request for the incremental data update is received within an unexpired data validity window for the cached data, wherein the data validity window is based on the determined time shift and in a case the incremental data update is received within the unexpired data validity window for the user, determining that the user is eligible for the incremental data update.