If it is a matter of finding the difference between two dates (in milliseconds) you can even run the following query.

DECLARE @d1 DATETIME, @d2 DATETIME

SELECT @d1 = '1/9/2008 11:30:24.123', @d2 = '1/10/2008'

SELECT DATEDIFF(millisecond, @d1, @d2) AS Diff

/*

Diff

-----------

44975877

*/

Or you can extract specific information from the date value using the following query and apply your required calculations.

DECLARE @d1 DATETIME, @d2 DATETIME

SELECT @d1 = '1/9/2008 11:30:24.123'

SELECT

DATEPART(year, @d1) AS Years,

DATEPART(month, @d1) AS Months,

DATEPART(day, @d1) AS Days,

DATEPART(hour, @d1) AS Hours,

DATEPART(minute, @d1) AS Minutes,

DATEPART(second, @d1) AS Seconds,

DATEPART(Millisecond, @d1) AS Milliseconds

/*

Years Months Days Hours Minutes Seconds Milliseconds

----------- ----------- ----------- ----------- ----------- ----------- ------------

2008 1 9 11 30 24 123

*/