SQL Server 2019

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-- September 7th
SELECT CONVERT(datetime, '2004-09-07 04:32:12.000');

-- July 9th (interpreted as Y-D-M in more thna half the languages in SQL Server)
SET LANGUAGE French;
SELECT CONVERT(datetime, '2004-09-07 04:32:12.000');

(No column name)

2004-09-07 04:32:12.000

(No column name)

2004-07-09 04:32:12.000

Le paramètre de langue est passé à Français.

-- September 13th
SET LANGUAGE us_english;
SELECT CONVERT(datetime, '2004-09-13 04:32:12.000');

(No column name)

2004-09-13 04:32:12.000

Changed language setting to us_english.

-- Error because no 13th month
SET LANGUAGE French;
SELECT CONVERT(datetime, '2004-09-13 04:32:12.000');
Msg 242 Level 16 State 3 Line 3
La conversion d'un type de données varchar en type de données datetime a créé une valeur hors limites.

-- However if we use style 21, it never fails.
SELECT CONVERT(datetime, '2004-09-07 04:32:12.000', 21);
SELECT CONVERT(datetime, '2004-09-13 04:32:12.000', 21);
SET LANGUAGE French;
SELECT CONVERT(datetime, '2004-09-07 04:32:12.000', 21);
SELECT CONVERT(datetime, '2004-09-13 04:32:12.000', 21);

(No column name)

2004-09-07 04:32:12.000

(No column name)

2004-09-13 04:32:12.000

(No column name)

2004-09-07 04:32:12.000

Le paramètre de langue est passé à Français.

(No column name)

2004-09-13 04:32:12.000

-- It also never fails if you use datetime2(3), but I would still
-- always specify the style number for clarity:
SELECT CONVERT(datetime2(3), '2004-09-07 04:32:12.000');
SELECT CONVERT(datetime2(3), '2004-09-13 04:32:12.000');
SET LANGUAGE French;
SELECT CONVERT(datetime2(3), '2004-09-07 04:32:12.000', 21);
SELECT CONVERT(datetime2(3), '2004-09-13 04:32:12.000', 21);

(No column name)

2004-09-07 04:32:12

(No column name)

2004-09-13 04:32:12

(No column name)

2004-09-07 04:32:12

Le paramètre de langue est passé à Français.

(No column name)

2004-09-13 04:32:12