Script to estimate backup and restore completion time in SQL Server

I used to get frequent mails from the users stating about when would be the backup will complete etc.

For this I used the below script which will provide the details of backup with the estimated time.

SELECT r.session_id
 ,r.command
 ,CONVERT(NUMERIC(6, 2), r.percent_complete) AS [Percent Complete]
 ,CONVERT(VARCHAR(20), DATEADD(ms, r.estimated_completion_time, GetDate()), 20)

 AS [ETA Completion Time]
 ,CONVERT(NUMERIC(10, 2), r.total_elapsed_time / 1000.0 / 60.0) AS [Elapsed Min]
 ,CONVERT(NUMERIC(10, 2), r.estimated_completion_time / 1000.0 / 60.0) AS [ETA Min]
 ,CONVERT(NUMERIC(10, 2), r.estimated_completion_time / 1000.0 / 60.0 / 60.0) AS [ETA Hours]
 ,CONVERT(VARCHAR(1000), (
   SELECT SUBSTRING(TEXT, r.statement_start_offset / 2, CASE 
      WHEN r.statement_end_offset = - 1
       THEN 1000
      ELSE (r.statement_end_offset - r.statement_start_offset) / 2
      END)
   FROM sys.dm_exec_sql_text(sql_handle)
   ))
FROM sys.dm_exec_requests r
WHERE command IN (
  'RESTORE DATABASE'
  ,'BACKUP DATABASE'
  )