USE tempdb;
GO 

-- xx Creo la tabella xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
CREATE TABLE #T1
  (
  [Id] int NOT NULL IDENTITY (1, 1)  PRIMARY KEY,
  [DaOr] datetime NOT NULL,
  [Note] varchar(50) NULL
  )  ON [PRIMARY]
GO

-- xx Inserisco i dati xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
SET IDENTITY_INSERT #T1 ON 
GO

INSERT #T1 ([Id], [DaOr], [Note]) VALUES 
(1, N'2015-02-02T13:05:00', N'04 Deve Restare'),
(2, N'2015-02-02T11:10:00', N'03 Deve Restare'),
(3, N'2015-02-02T12:00:00', N'Elimina'),
(9, N'2015-12-10T15:32:00', N'Elimina'),
(10, N'2015-12-10T15:00:00', N'06 Deve Restare'),
(11, N'2015-12-10T16:52:00', N'07 Deve Restare'),
(12, N'2015-12-12T23:00:30', N'08 Deve Restare'),
(13, N'2015-06-04T22:00:00', N'05 Deve Restare'),
(14, N'2015-02-02T10:40:40', N'Elimina'),
(15, N'2015-01-02T14:00:08', N'01 Deve Restare'),
(16, N'2015-02-02T10:00:00', N'02 Deve Restare');
GO

SET IDENTITY_INSERT #T1 OFF
GO

-- xx mostro i dati prima della routine xxxxxxxxxxxxxxxxxxxxxx
SELECT [Id], [DaOr], [Note] FROM #T1 ORDER BY [DaOr];
GO

-- *****************************************************************************
-- xx La Procedura vera e propria xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

-- 3600 La approssimazione in secondi per ritenere gli orari duplicati  ( 1 ora )
DECLARE @Appx as int     
SET @Appx = 3600

-- la OldDate di Base assunta per il 1° record,  deve essere la minimissima ammissibile in modo che il 1° record sia sempre mantenuto
DECLARE @Base AS Datetime        
SET @Base = (SELECT Min(DaOr) FROM #T1) 
SET @Base = DATEADD(s, -(@Appx+1000), @Base)
--  print @Base

--dichiaro le variabili da leggere nel cursore
DECLARE @Idxx AS int
DECLARE @OlDa AS datetime   
DECLARE @NwDa AS datetime                    

DECLARE Curs CURSOR FOR                      
SELECT [Id], [DaOr] FROM #T1 ORDER BY [DaOr]

OPEN Curs  
FETCH NEXT FROM Curs INTO @Idxx, @NwDa

SET @OlDa = @Base

  WHILE @@FETCH_STATUS = 0 
    BEGIN

      IF @NwDa > DATEADD(s, @Appx, @OlDa)
        BEGIN
          --  print CAST(@OlDa AS varchar) + '  ' + CAST(@NwDa AS varchar) + '  mantieni  '  +  CAST((DATEADD(s, @Appx, @OlDa)) AS varchar) + '  ' + CAST(@Idxx AS varchar)
          SET @OlDa = @NwDa
        END
      ELSE
        BEGIN
          --  print CAST(@OlDa AS varchar) + '  ' + CAST(@NwDa AS varchar) + '  elimina  '  +  CAST((DATEADD(s, @Appx, @OlDa)) AS varchar) + '  ' + CAST(@Idxx AS varchar)
          DELETE FROM #T1 WHERE Id=@Idxx
        END

      FETCH NEXT FROM Curs INTO @Idxx, @NwDa  
    END

CLOSE Curs
DEALLOCATE Curs

-- xx Fine della procedura xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
-- *****************************************************************************************

-- xx mostro i dati dopo la routine xxxxxxxxxxxxxxxxxxxxxx
SELECT [Id], [DaOr], [Note] FROM #T1 ORDER BY [DaOr];
GO

-- xx faccio pulizia nel  tempdb xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
DROP TABLE #T1;
GO

-- xx Finito