Query to Find time remaining to complete database backup or restore in SQL 2005

Query to Find time remaining to complete database backup or restore in SQL 2005

USE master
GO

SELECT
          Percent_Complete,
          Start_Time ,
          Command,
          b.Name AS DatabaseName, --Sometimes this will be "Main" as the database will not be accesiable.
          DATEADD(ms,estimated_completion_time,GETDATE()) AS RemainTime,
          (estimated_completion_time/1000/60) AS MinutesToFinish
FROM sys.dm_exec_requests a
          INNER JOIN sys.databases b
          ON a.database_id = b.database_id
WHERE
          Command like '%Restore%'
          OR Command like '%Backup%'
          AND Estimated_Completion_Time > 0