Database application query problem

[cool11]

Thanks for your reply and for the links, This is my current code:

    rs1.Open "CL1", ds1, adOpenDynamic, adLockOptimistic
    que = "SELECT DateDiff('h',0,Sum(end_time-call_in)) &  Format(Sum(end_time-call_in), ':nn:ss') as TotalTime "
    que = que + "From CL1 WHERE call_in Between #" + Trim(Text1.Text) + "# and #" + Trim(Text2.Text) + "#"
    que = que & " AND Format(call_in,'w') NOT IN(1,7) "
    que = que & " AND Int(call_in) NOT IN"
    
    If (List1.ListCount = 1) Then
    que = que & "(" & Int(CDate(List1.List(iloop))) & ") "
    Else
    For iloop = 0 To List1.ListCount - 1
    TempArray() = Split(List1.List(iloop), "/")
    MyDate = DateSerial(TempArray(2), TempArray(0), TempArray(1))

     If (iloop = List1.ListCount - 1) Then
    que = que & " " & Int(MyDate) & ") "
    Else
    If (iloop > 0) Then
    que = que & " " & Int(MyDate) & ", "
    Else
    que = que & " (" & Int(MyDate) & ", "
    End If
    End If
    
    Next iloop
    End If
    que = que & " AND end_time Is Not Null;"
    Set rs1 = ds1.Execute(que)
    MSFlexGrid1.TextMatrix(1, 5) = rs1("TotalTime").Value
    Text4.Text = que

The query now has no errors but the outcome is the same as the result of excluding weekends(the section for excluding dates is not effective even though it looks correct). Dunno where is it wrong?
The query on running looks like:

SELECT DateDiff('h',0,Sum(end_time-call_in)) & Format(Sum(end_time-call_in), ':nn:ss') as TotalTime From CL1 WHERE call_in Between #08/01/2008# and #08/31/2008# AND Format(call_in,'w') NOT IN(1,7) AND Int(call_in) NOT IN (8/28/2008, 8/29/2008, 8/22/2008, 8/21/2008) AND end_time Is Not Null;

Thanks