How to calculate age in T-SQL with years, months,

Question

What would be the best way to calculate someone's age in years, months, and days in T-SQL (SQL Server 2000)?

The datediff function doesn't handle year boundaries well, plus getting the months and days separate will be a bear. I know I can do it on the client side relatively easily, but I'd like to have it done in my stored procedure.

Answer 1

Here is some T-SQL that gives you the number of years, months, and days since the day specified in @date. It takes into account the fact that DATEDIFF() computes the difference without considering what month or day it is (so the month diff between 8/31 and 9/1 is 1 month) and handles that with a case statement that decrements the result where appropriate.

DECLARE @date datetime, @tmpdate datetime, @years int, @months int, @days int
SELECT @date = '2/29/04'

SELECT @tmpdate = @date

SELECT @years = DATEDIFF(yy, @tmpdate, GETDATE()) - CASE WHEN (MONTH(@date) > MONTH(GETDATE())) OR (MONTH(@date) = MONTH(GETDATE()) AND DAY(@date) > DAY(GETDATE())) THEN 1 ELSE 0 END
SELECT @tmpdate = DATEADD(yy, @years, @tmpdate)
SELECT @months = DATEDIFF(m, @tmpdate, GETDATE()) - CASE WHEN DAY(@date) > DAY(GETDATE()) THEN 1 ELSE 0 END
SELECT @tmpdate = DATEADD(m, @months, @tmpdate)
SELECT @days = DATEDIFF(d, @tmpdate, GETDATE())

SELECT @years, @months, @days

Answer 2

I use this Function I modified (the Days part) From @Dane answer: https://stackoverflow.com/a/57720/2097023

CREATE FUNCTION dbo.EdadAMD
    (
        @FECHA DATETIME
    )
    RETURNS NVARCHAR(10)
    AS
    BEGIN
        DECLARE
            @tmpdate DATETIME
          , @years   INT
          , @months  INT
          , @days    INT
          , @EdadAMD NVARCHAR(10);

        SELECT @tmpdate = @FECHA;

        SELECT @years = DATEDIFF(yy, @tmpdate, GETDATE()) - CASE
                                          WHEN (MONTH(@FECHA) >    MONTH(GETDATE()))
                                             OR (
                                                MONTH(@FECHA) = MONTH(GETDATE())
                                          AND DAY(@FECHA) > DAY(GETDATE())
                                          ) THEN
                                                1
                                            ELSE
                                                0
                                    END;
    SELECT @tmpdate = DATEADD(yy, @years, @tmpdate);
    SELECT @months = DATEDIFF(m, @tmpdate, GETDATE()) - CASE
                              WHEN DAY(@FECHA) > DAY(GETDATE()) THEN
                                                            1
                                                        ELSE
                                                            0
                                                    END;
    SELECT @tmpdate = DATEADD(m, @months, @tmpdate);

    IF MONTH(@FECHA) = MONTH(GETDATE())
       AND DAY(@FECHA) > DAY(GETDATE())
          SELECT @days = 
            DAY(EOMONTH(GETDATE(), -1)) - (DAY(@FECHA) - DAY(GETDATE()));
    ELSE
        SELECT @days = DATEDIFF(d, @tmpdate, GETDATE());

    SELECT @EdadAMD = CONCAT(@years, 'a', @months, 'm', @days, 'd');

    RETURN @EdadAMD;

END; 
GO

It works pretty well.

Answer 3

Simple way to get age as text is as below:

Select cast((DATEDIFF(m, date_of_birth, GETDATE())/12) as varchar) + ' Y & ' + 
       cast((DATEDIFF(m, date_of_birth, GETDATE())%12) as varchar) + ' M' as Age

Results Format will be:

**63 Y & 2 M**

Answer 4

Quite Old question, but I want to share what I have done to calculate age

    Declare @BirthDate As DateTime
Set @BirthDate = '1994-11-02'

SELECT DATEDIFF(YEAR,@BirthDate,GETDATE()) - (CASE 
WHEN MONTH(@BirthDate)> MONTH(GETDATE()) THEN 1 
WHEN MONTH(@BirthDate)= MONTH(GETDATE()) AND DAY(@BirthDate) > DAY(GETDATE()) THEN 1 
Else 0 END)

Answer 5

SELECT DOB AS Birthdate ,
       YEAR(GETDATE()) AS ThisYear,
       YEAR(getdate()) - YEAR(DOB) AS Age
FROM tableprincejain

Answer 6

Implemented by arithmetic with ISO formatted date.

declare @now date,@dob date, @now_i int,@dob_i int, @days_in_birth_month int
declare @years int, @months int, @days int
set @now = '2013-02-28' 
set @dob = '2012-02-29' -- Date of Birth

set @now_i = convert(varchar(8),@now,112) -- iso formatted: 20130228
set @dob_i = convert(varchar(8),@dob,112) -- iso formatted: 20120229
set @years = ( @now_i - @dob_i)/10000
-- (20130228 - 20120229)/10000 = 0 years

set @months =(1200 + (month(@now)- month(@dob))*100 + day(@now) - day(@dob))/100 %12
-- (1200 + 0228 - 0229)/100 % 12 = 11 months

set @days_in_birth_month = day(dateadd(d,-1,left(convert(varchar(8),dateadd(m,1,@dob),112),6)+'01'))
set @days = (sign(day(@now) - day(@dob))+1)/2 * (day(@now) - day(@dob))
          + (sign(day(@dob) - day(@now))+1)/2 * (@days_in_birth_month - day(@dob) + day(@now))
-- ( (-1+1)/2*(28 - 29) + (1+1)/2*(29 - 29 + 28))
-- Explain: if the days of now is bigger than the days of birth, then diff the two days
--          else add the days of now and the distance from the date of birth to the end of the birth month 
select @years,@months,@days -- 0, 11, 28 

Test Cases

The approach of days is different from the accepted answer, the differences shown in the comments below:

       dob        now  years  months  days 
2012-02-29 2013-02-28      0      11    28  --Days will be 30 if calculated by the approach in accepted answer. 
2012-02-29 2016-02-28      3      11    28  --Days will be 31 if calculated by the approach in accepted answer, since the day of birth will be changed to 28 from 29 after dateadd by years. 
2012-02-29 2016-03-31      4       1     2
2012-01-30 2016-02-29      4       0    30
2012-01-30 2016-03-01      4       1     2  --Days will be 1 if calculated by the approach in accepted answer, since the day of birth will be changed to 30 from 29 after dateadd by years.
2011-12-30 2016-02-29      4       1    30

An short version of Days by case statement:

set @days = CASE WHEN day(@now) >= day(@dob) THEN day(@now) - day(@dob)
                 ELSE @days_in_birth_month - day(@dob) + day(@now) END

If you want the age of years and months only, it could be simpler

set @years = ( @now_i/100 - @dob_i/100)/100
set @months =(12 + month(@now) - month(@dob))%12 
select @years,@months -- 1, 0

NOTE: A very useful link of SQL Server Date Formats