Converting integer hours to datetime format in MS SQL SERVER 

DECLARE @DateTimeHours datetime

DECLARE @IntHours  int

SET @IntHours  =  3

SET @DateTimeHours = CONVERT(datetime,CONVERT(varchar, DATEADD(SECOND, @IntHours *3600, 0), 24))

OUTPUT:

1900-01-01 03:00:00.000

If you want to convert in present datetime:

 SET @DateTimeHours = CONVERT(varchar,GETDATE(),103) + CONVERT

(datetime,CONVERT(varchar, DATEADD(SECOND, @IntHours *3600, 0), 24))

OUTPUT:

2013-08-12 03:00:00.000