Thank you very much.I think no need to DATEADD function. It automatically calculate adding the days with base date.--SimplifiedSELECT DATEPART(YEAR, DATEDIFF(DAY, bithdate,today_date)) - 1900 AS [YEARS], DATEPART(MONTH, DATEDIFF(DAY, bithdate,today_date))-1 AS [MONTHS], DATEPART(DAY, DATEDIFF(DAY, bithdate,today_date))-1 AS [DAYS], DATEPART(DAY, DATEDIFF(DAY, bithdate,today_date))-1 AS [DAYS]FROM (VALUES('2000-05-31', '2013-04-01'),--12-10-2('1990-01-02','2013-10-30'),--23-9-28('2010-01-01','2011-01-01'))D (bithdate, today_date);