C'est bon, le problème venait du format date.
Dim DateDeb2, DateFin2 As Double
Dim DateDeb, DateFin As Date
DateDeb = Sheets("PLANNING").Range("E8").Value
DateDeb2 = Format(DateDeb, "##")
DateFin = Sheets("PLANNING").Range("AW8").Value
DateFin2 = Format(DateFin, "##")
With Sheets("DONNÉES")
.Range("C:C").NumberFormat = "General"
.ListObjects("TableauDONNÉES").Range.AutoFilter Field:=3, _
Criteria1:=">=" & DateDeb2, Operator:=xlAnd, Criteria2:="<=" & DateFin2
End With
With Sheets("DONNÉES")
.ListObjects("TableauDONNÉES").Range.AutoFilter Field:=3
.Range("C:C").NumberFormat = "m/d/yyyy"
End With