Masquer lignes suivants une cellule

Private Sub Worksheet_Change(ByVal Target As Range)
    Dim c As Range, rg As Range
    
    Application.ScreenUpdating = False

    Cells.EntireRow.Hidden = False
    If Target = [B1] Then
        Set rg = ActiveSheet.Range("B1:B" & ActiveSheet.Range("B65000").End(xlUp).Row)
        For Each c In rg
            If Month(c) <> Month([B1]) Then c.EntireRow.Hidden = True
        Next c
    End If
    
    Application.ScreenUpdating = True
    
End Sub