When was SQL Server database Last used??

If we want to remove the databases from the server which are not getting used from a long time. In this case first we need the name of databases which are not used from a long time. We can use below script to find the same.  

SELECT DBName, MAX(LastUsedDate) LastUsedDate

FROM

    (SELECT

        DB_NAME(database_id) DBName

        , last_user_seek

        , last_user_scan

        , last_user_lookup

        , last_user_update

    FROM sys.dm_db_index_usage_stats) AS PvtTable

UNPIVOT 

    (LastUsedDate FOR last_user_access IN

        (last_user_seek

        , last_user_scan

        , last_user_lookup

        , last_user_update)

    ) AS UnpvtTable

GROUP BY DBName

ORDER BY LastUsedDate

Thanks!!