Via using day
you can reach the result:
select
datediff(month,'2012-April-09','2013-April-08') MonthsInService
,datediff(day,'2012-April-09','2013-April-08')/365 YearsInService
Output:
12 0
or use function for maximum precision:
CREATE FUNCTION [dbo].[getFullYears]
(
@dateX datetime,
@dateY datetime
)
RETURNS int
AS
BEGIN
DECLARE @y int
SET @y =DATEDIFF(year,@dateX,@dateY)
IF (@dateY < DATEADD(year, @y, @dateX)) SET @y = @y -1
RETURN @y
END
select dbo.getFullYears('2012-April-09','2013-April-09') --1
select dbo.getFullYears('2012-April-09','2013-April-08') --0
For months calculation you can refer here: Calculating number of full months between two dates in SQL