SQL Server 2022

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CREATE TABLE [dbo].[TEST](
    [CPR] [varchar](50) NULL,
    [Period_start] [date] NULL,
    [Period_End] [date] NULL,
    [Funktion] [varchar](50) NULL,
    [Gruppe] [varchar](50) NULL
) ON [PRIMARY]

INSERT [dbo].[TEST] ([CPR], [Period_start], [Period_End], [Funktion], [Gruppe]) VALUES 
    (N'111111-1111', CAST(N'2022-09-13' AS Date), CAST(N'2022-09-13' AS Date), N'53859', N'002'),
    (N'111111-1111', CAST(N'2022-12-21' AS Date), CAST(N'2022-12-21' AS Date), N'53859', N'002'),
    (N'111111-1111', CAST(N'2022-12-31' AS Date), CAST(N'2022-12-31' AS Date), N'53859', N'002'),
    (N'111111-1111', CAST(N'2022-12-31' AS Date), CAST(N'2022-12-31' AS Date), N'53859', N'002'),
    (N'111111-1111', CAST(N'2022-07-11' AS Date), CAST(N'2022-07-11' AS Date), N'53859', N'002'),
    (N'111111-1111', CAST(N'2022-07-11' AS Date), CAST(N'2022-07-11' AS Date), N'53859', N'002'),
    (N'111111-1111', CAST(N'2022-07-13' AS Date), CAST(N'2022-07-13' AS Date), N'53859', N'002'),
    (N'111111-1111', CAST(N'2022-07-14' AS Date), CAST(N'2022-07-14' AS Date), N'53859', N'002'),
    (N'111111-1111', CAST(N'2022-07-22' AS Date), CAST(N'2022-07-22' AS Date), N'53859', N'002'),
    (N'111111-1111', CAST(N'2022-08-17' AS Date), CAST(N'2022-08-17' AS Date), N'53859', N'002'),
    (N'111111-1111', CAST(N'2022-11-07' AS Date), CAST(N'2022-11-07' AS Date), N'53859', N'002'),
    (N'111111-1111', CAST(N'2022-11-24' AS Date), CAST(N'2022-11-24' AS Date), N'53859', N'002')

12 rows affected

CPR	Funktion	Gruppe	Period_start	Period_End	Previous_EOM_Period_End	(No column name)
111111-1111	53859	002	2022-07-01	2022-07-31	null	1
111111-1111	53859	002	2022-07-01	2022-07-31	2022-07-31	1
111111-1111	53859	002	2022-07-01	2022-07-31	2022-07-31	1
111111-1111	53859	002	2022-07-01	2022-07-31	2022-07-31	1
111111-1111	53859	002	2022-07-01	2022-07-31	2022-07-31	1
111111-1111	53859	002	2022-08-01	2022-08-31	2022-07-31	1
111111-1111	53859	002	2022-09-01	2022-09-30	2022-08-31	1
111111-1111	53859	002	2022-11-01	2022-11-30	2022-09-30	2
111111-1111	53859	002	2022-11-01	2022-11-30	2022-11-30	2
111111-1111	53859	002	2022-12-01	2022-12-31	2022-11-30	2
111111-1111	53859	002	2022-12-01	2022-12-31	2022-12-31	2
111111-1111	53859	002	2022-12-01	2022-12-31	2022-12-31	2

Warning: Null value is eliminated by an aggregate or other SET operation.