Just some code to get the time part only from a DateTime field (is SQL Server 2000 or 2005), with the date set to a reference date
declare @timetest datetime
declare @refdate datetime
set @timetest = getdate()
set @refdate = '30 Dec 1899 00:00:00'
select @timetest
, @refdate
, dateadd(day, datediff(day, @refdate , @timetest), @refdate ) -- date part only
, dateadd(day, datediff(day, @refdate , @timetest) * -1, @timetest) -- time part only, with reference date
Instead of @refdate, you could use 0.