The Shipment Manager displays 3 months of shipment data at a time. Showing more than 3 months of shipment data at a time would affect the performance of the application.
If you want to see shipments older than 90 days, the "Show Filters" option allows users to conduct a custom search of up to 5 years by entering a date range of up to 90 days at a time. Keep in mind, the Shipment Manager will only display shipments filed through the AESDirect portal.