check this
DECLARE @di_date BIGINT
SET @di_date=19820201150000
DECLARE @ds_date VARCHAR(20)
SET @ds_date=CONVERT(VARCHAR(20), @di_date )
select
Convert(time,Dateadd(SECOND,
Right(@ds_date,2)/1,
Dateadd(MINUTE,
Right(@ds_date,4)/100,
Dateadd(hour,
Right(@ds_date,6)/10000,
'1900-01-01')))) +
convert(datetime,LEFT(@ds_date,8)) as DateConverted
credits http://rdineshkumar.wordpress.com/tag/how-to-convert-yyyymmddhhmmss-to-datetimedatetime-in-sql-server