Diffence between two date in sql server

here you go: CREATE PROCEDURE dbo.CalculateAge @dayOfBirth datetime AS DECLARE @today datetime, @thisYearBirthDay datetime DECLARE @years int, @months int, @days int SELECT @today = GETDATE() SELECT @thisYearBirthDay = DATEADD(year, DATEDIFF(year, @dayOfBirth, @today), @dayOfBirth) SELECT @years = DATEDIFF(year, @dayOfBirth, @today) - (CASE WHEN @thisYearBirthDay > @today THEN 1 ELSE 0 END) SELECT @months = MONTH(@today - @thisYearBirthDay) - 1 SELECT @days = DAY(@today - @thisYearBirthDay) - 1 SELECT @years, @months, @days GO MARK this as Accepted Answer if you like it...