Insertion automatique de ligne vide entre plusieurs heures

Sub Lignes2()
Const M As Double = 1 / 1440
Dim i&, T!, R As Range
T = 1
Application.ScreenUpdating = False
With Sheets("Feuil1")
    For i = .Cells(Rows.Count, 1).End(xlUp).Row To 2 Step -1
        'Ajout
        If Format(.Cells(i, 1).Value, "hh:mm:00") <> Format(T, "hh:mm:00") Then
            .Rows(i + 1).Insert
            .Cells(i + 1, 1).Value = Format(T, "hh:mm:00")
            .Cells(i + 1, 1).Interior.ColorIndex = 35
            i = i + 1
        ' Doublon
        ElseIf Format(.Cells(i, 1).Value, "hh:mm:00") = _
                Format(.Cells(i - 1, 1).Value, "hh:mm:00") Then
            Set R = Union(.Rows(i), IIf(R Is Nothing, Rows(i), R))
            T = T + M
        End If
        T = T - M
    Next i
    While Format(.Cells(2, 1).Value, "hh:mm:00") <> "00:00:00"
        .Rows(2).Insert CopyOrigin:=xlFormatFromRightOrBelow
        .Cells(2, 1).Value = Format(T, "hh:mm:00")
        .Cells(2, 1).Interior.ColorIndex = 35
        T = T - M
    Wend
    If Not R Is Nothing Then R.Select ' Pour visualiser la plage
    'If Not R Is Nothing Then R.Delete ' pour supprimer la plage
End With
Application.ScreenUpdating = True
End Sub