Try this:
DECLARE @ToDate DATETIME = DATEADD(dd, DATEDIFF(dd, 0, GETDATE()), 0)
DECLARE @FromDate DATETIME = DATEADD(dd, -5, @ToDate)
SELECT <Field_list>
FROM <TableName>
WHERE DateTimeField BETWEEN @FromDate AND @ToDate
Note: change the code to your needs
See also:
DATEADD()[
^]
DATEDIFF()[
^]