SQL Server 2019

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select @@version;

(No column name)

Microsoft SQL Server 2019 (RTM-CU6) (KB4563110) - 15.0.4053.23 (X64) 
	Jul 25 2020 11:26:55 
	Copyright (C) 2019 Microsoft Corporation
	Express Edition (64-bit) on Windows Server 2019 Standard 10.0 <X64> (Build 17763: ) (Hypervisor)

create table vertrag (beginn datetime, ende datetime);
insert into vertrag values 
(CONVERT(DATETIME,'13/12/2021 23:24',103),CONVERT(DATETIME,'11/01/2022 11:11',103));
insert into vertrag values 
(CONVERT(DATETIME,'13/12/2021 23:24',103),CONVERT(DATETIME,'12/02/2022 12:12',103));
2 rows affected

select * from vertrag;

beginn
ende

2021-12-13 23:24:00.000
2022-01-11 11:11:00.000

2021-12-13 23:24:00.000
2022-02-12 12:12:00.000

-- 2021 kein Treffer
select * from vertrag 
 where CONVERT(DATETIME,'10/02/2021',103) between beginn and ende;

beginn
ende

-- 2022 Treffer
select * from vertrag 
 where CONVERT(DATETIME,'10/02/2022',103) between beginn and ende;

beginn
ende

2021-12-13 23:24:00.000
2022-02-12 12:12:00.000

-- 2023 kein Treffer
select * from vertrag 
 where CONVERT(DATETIME,'10/02/2023',103) between beginn and ende;

beginn
ende

-- 2022 beide
select * from vertrag 
 where CONVERT(DATETIME,'10/01/2022',103) between beginn and ende;

beginn
ende

2021-12-13 23:24:00.000
2022-01-11 11:11:00.000

2021-12-13 23:24:00.000
2022-02-12 12:12:00.000

beginn	ende
2021-12-13 23:24:00.000	2022-01-11 11:11:00.000
2021-12-13 23:24:00.000	2022-02-12 12:12:00.000