--- put following code In a module without the --- marks 
Option Explicit 
 
Sub filter_less_then_today() 
     ' declare as date
    Dim dDate As Date 
     ' declare as long (using numbering of excel for dates)
    Dim lDate As Long 
     ' store answer to msgbox
    Dim answer As Long 
     ' store today in datevariabele
    dDate = DateSerial(year(Now), month(Now), day(Now)) 
     ' save as number
    lDate = dDate 
     ' answer to question
    If Worksheets(1).AutoFilterMode = True Then 
        answer = MsgBox("Turn autofilter off (yes)" & vbCrLf & _ 
        "Filter on date until now (no)" & vbCrLf, vbYesNoCancel, "Filtering ...") 
        Select Case answer 
             ' yes
        Case 6 
            Range("B1").AutoFilter 
             ' no
        Case 7 
             ' cancel
        Case 2 
        End Select 
    Else 
         ' apply filter yes or no
        answer = MsgBox("Filter on date until now (yes)" & vbCrLf & _ 
        "Do nothing and leave it as it is (no)" & vbCrLf, vbYesNo, "Filtering ...") 
        Select Case answer 
             ' yes
        Case 6 
            Range("B1").AutoFilter field:=1, Criteria1:="<" & lDate 
             ' no
        Case 7 
        End Select 
    End If 
End Sub 
--- End of code module