WAN Bandwidth Utilization on Business hours only

I am using the SQL command below to generate weekdays report (business hour only) but to find out that it still covers the non-business hours. Please advise. Thanks.

DECLARE @StartDate DateTime

DECLARE @EndDate DateTime

SET @StartDate = '2014-12-08 07:00:00'

SET @EndDate = '2014-12-12 19:00:00'

set nocount on

create table #InterfaceIds (

      InterfaceID int NOT NULL,

      CONSTRAINT [PK_#InterfaceIds] PRIMARY KEY CLUSTERED

      (

            InterfaceID ASC

      )

)   

insert into #InterfaceIds

    SELECT DISTINCT A.InterfaceID

    FROM dbo.InterfaceTraffic A

    WHERE A.DateTime >= @StartDate AND A.DateTime <=  @EndDate

SELECT Interfaces.InterfaceId,

Nodes.NodeID,

Nodes.Caption AS NodeName,

Nodes.City,

Interfaces.Caption AS Interface_Caption,

Interfaces.InterfaceIcon AS Interface_Icon,

Interfaces.InterfaceSpeed,

ROUND(dbo.GetInBps95th(InterfaceID, @StartDate, @EndDate) / InBandwidth * 100,0) AS PercentIN,

ROUND(dbo.GetOutBps95th(InterfaceID, @StartDate, @EndDate)/ OutBandwidth * 100,0) AS PercentOUT

FROM Nodes

INNER JOIN Interfaces ON (Nodes.NodeID = Interfaces.NodeID)

WHERE (Interfaces.InterfaceID in (4515,4517,4215,4214,3703,3228,4498,4496,4548,4550,4633,4635,2723,2728,3222,3226,3140,3128,3135,4320,4316,4318,4590,3170,3164,3167,3020,3172,3014,4544,4546,3742,3180,4739,4741,8780) )

  AND (Interfaces.InterfaceSpeed != 0)

ORDER BY 8 DESC, 9 DESC

DROP TABLE #InterfaceIds