SQL Server 2022

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CREATE OR ALTER FUNCTION dbo.WaitForMS
(
    @Milliseconds smallint
)
RETURNS integer
WITH RETURNS NULL ON NULL INPUT
AS
BEGIN
    DECLARE 
        @Start datetime2 =
            SYSUTCDATETIME(),
        @End datetime2 =
            DATEADD
            (
                MILLISECOND,
                @Milliseconds,
                SYSUTCDATETIME()
            );

DECLARE 
        @Context varchar(8000),
        @ActualDelay integer,
        @JSON nvarchar(max) = 
            N'{}',
        @Now nvarchar(max) = 
            CONVERT
            (
                nvarchar(max), 
                SYSUTCDATETIME(), 
                126
            );

SET @JSON = 
        JSON_MODIFY
        (
            @JSON,
            'lax $.start_time', 
            @Now
        );

WHILE SYSUTCDATETIME() BETWEEN @Start AND @End
    BEGIN
        DECLARE @Spin bit;
    END;

SELECT 
        @ActualDelay = 
            CONVERT
            (
                nvarchar(max), 
                DATEDIFF
                (
                    MILLISECOND, 
                    @Start, 
                    SYSUTCDATETIME()
                )
            ),
        @Now = 
            CONVERT
            (
                nvarchar(max), 
                SYSUTCDATETIME(), 
                126
            );

SET @JSON = 
        JSON_MODIFY
        (
            @JSON, 
            'lax $.end_time', 
            @Now
        );

SET @JSON = 
        JSON_MODIFY
        (
            @JSON, 
            'lax $.actual_delay_ms', 
            @ActualDelay
        );

SET @Context = 
        CONVERT
        (
            varchar(8000), 
            @JSON
        );

EXECUTE sys.sp_set_session_context
        @key = N'dbo.WaitForMS',
        @value = @Context,
        @read_only = 0;

RETURN @ActualDelay;
END;

Actual Delay ms	Details
547	{"start_time":"2026-01-14T15:32:05.6209394","end_time":"2026-01-14T15:32:06.1678262","actual_delay_ms":547}