--測試數據
DECLARE @t TABLE(ID int,Name varchar(10),Birthday datetime)
INSERT @t SELECT 1,'aa','1999-01-01'
UNION ALL SELECT 2,'bb','1996-02-29'
UNION ALL SELECT 3,'bb','1934-03-01'
UNION ALL SELECT 4,'bb','1966-04-01'
UNION ALL SELECT 5,'bb','1997-05-01'
UNION ALL SELECT 6,'bb','1922-11-21'
UNION ALL SELECT 7,'bb','1989-12-11'

DECLARE @dt1 datetime,@dt2 datetime

--查詢 2003-12-05 至 2004-02-28 生日的記錄
SELECT @dt1='2003-12-05',@dt2='2004-02-28'
SELECT * FROM @t
WHERE DATEADD(Year,DATEDIFF(Year,Birthday,@dt1),Birthday)
		BETWEEN @dt1 AND @dt2
	OR DATEADD(Year,DATEDIFF(Year,Birthday,@dt2),Birthday)
		BETWEEN @dt1 AND @dt2
/*--結果
ID         Name       Birthday
---------------- ---------------- --------------------------
1           aa         1999-01-01 00:00:00.000
7           bb         1989-12-11 00:00:00.000
--*/

--查詢 2003-12-05 至 2006-02-28 生日的記錄
SET @dt2='2006-02-28'
SELECT * FROM @t
WHERE DATEADD(Year,DATEDIFF(Year,Birthday,@dt1),Birthday)
		BETWEEN @dt1 AND @dt2
	OR DATEADD(Year,DATEDIFF(Year,Birthday,@dt2),Birthday)
		BETWEEN @dt1 AND @dt2
/*--查詢結果
ID         Name       Birthday
---------------- ----------------- --------------------------
1           aa         1999-01-01 00:00:00.000
2           bb         1996-02-29 00:00:00.000
7           bb         1989-12-11 00:00:00.000
--*/