Changer l'année d'une date

Sub test()
Dim nbLignes As Long, i As Long

    With ThisWorkbook.Sheets("Feuil1")
        nbLignes = .Range("E" & .Rows.Count).End(xlUp).Row
        
        For i = 10 To nbLignes
            If IsDate(.Range("E" & i)) Then
                If Year(.Range("E" & i)) = 2020 Then .Range("E" & i) = DateSerial(2010, Month(.Range("E" & i)), Day(.Range("E" & i)))
            End If
        Next i
    End With
End Sub

Option Explicit
Sub test()
Dim c As Range
Application.ScreenUpdating = False
For Each c In Range("E10:E" & Range("E65536").End(xlUp).Row)
    If IsDate(c) Then
        If Year(c) = 2020 Then c = DateSerial(2010, Month(c), Day(c))
    End If
Next c
Application.ScreenUpdating = True
End Sub

=SI(E10="";"";DATE(ANNEE(E10)-10*(ANNEE(E10)=2020);MOIS(E10);JOUR(E10)))