Private Sub Worksheet_Change(ByVal Target As Range)

If Target.Row >= 1 And Target.Row <= 10 And Target.Column = 2 Then
    Target.Offset(0, -1) = Format(Date, "yyyy-mm-dd")
End If

End Sub

Private Sub Worksheet_Change(ByVal Target As Range)

Dim oRange As Range
Set oRange = Me.Range("B2:C10")

If Target.Row >= oRange.Cells(1).Row And Target.Row <= oRange.Cells(oRange.Cells.Count).Row _
    And Target.Column >= oRange.Cells(1).Column And Target.Column <= oRange.Cells(oRange.Cells.Count).Column Then
    Application.EnableEvents = False
    Target.Offset(0, -1) = Format(Date, "yyyy-mm-dd")
    Application.EnableEvents = True
End If

Set oRange = Nothing

End Sub

Private Sub Worksheet_Change(ByVal Target As Range)

    Dim dat As String
    dat = Format(Date, "yyyy-mm-dd")
    ActiveCell.Offset(-1, -1) = dat

End Sub