SQL Server 2017

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select @@version;

IF OBJECT_ID('tempdb.dbo.#MyTable', 'U') IS NOT NULL
    DROP TABLE #MyTable;

CREATE TABLE #MyTable
(
    id INTEGER NOT NULL
  , date DATETIME NOT NULL
);
INSERT INTO #MyTable (id, date) VALUES (2380, '10/30/12 09:00:00');
INSERT INTO #MyTable (id, date) VALUES (2380, '10/30/12 09:05:00');
INSERT INTO #MyTable (id, date) VALUES (2380, '10/30/12 09:10:00');
INSERT INTO #MyTable (id, date) VALUES (2380, '10/30/12 09:15:00');
INSERT INTO #MyTable (id, date) VALUES (2381, '10/30/12 10:00:00');
INSERT INTO #MyTable (id, date) VALUES (2381, '10/30/12 10:05:00');
INSERT INTO #MyTable (id, date) VALUES (2381, '10/30/12 10:10:00');
INSERT INTO #MyTable (id, date) VALUES (2381, '10/30/12 10:15:00');
INSERT INTO #MyTable (id, date) VALUES (2382, '10/30/12 11:00:00');
INSERT INTO #MyTable (id, date) VALUES (2382, '10/30/12 11:05:00');
INSERT INTO #MyTable (id, date) VALUES (2382, '10/30/12 10:10:00');
INSERT INTO #MyTable (id, date) VALUES (2382, '10/30/12 10:15:00');
INSERT INTO #MyTable (id, date) VALUES (2382, '10/30/12 12:15:00');
INSERT INTO #MyTable (id, date) VALUES (2382, '10/30/12 10:15:30');

SELECT     a.*
         , CONVERT(NVARCHAR(8), a.date - b.ReferenceDate, 108) AS duration
FROM       #MyTable AS a
INNER JOIN (
	SELECT id, MIN(date) AS ReferenceDate 
	FROM #MyTable GROUP BY id) AS b ON a.id = b.id;

(No column name)
Microsoft SQL Server 2017 (RTM-CU15-GDR) (KB4505225) - 14.0.3192.2 (X64) Jun 15 2019 00:45:05 Copyright (C) 2017 Microsoft Corporation Express Edition (64-bit) on Windows Server 2019 Standard 10.0 <X64> (Build 17763: ) (Hypervisor)

id	date	duration
2380	30/10/2012 09:00:00	00:00:00
2380	30/10/2012 09:05:00	00:05:00
2380	30/10/2012 09:10:00	00:10:00
2380	30/10/2012 09:15:00	00:15:00
2381	30/10/2012 10:00:00	00:00:00
2381	30/10/2012 10:05:00	00:05:00
2381	30/10/2012 10:10:00	00:10:00
2381	30/10/2012 10:15:00	00:15:00
2382	30/10/2012 11:00:00	00:50:00
2382	30/10/2012 11:05:00	00:55:00
2382	30/10/2012 10:10:00	00:00:00
2382	30/10/2012 10:15:00	00:05:00
2382	30/10/2012 12:15:00	02:05:00
2382	30/10/2012 10:15:30	00:05:30