如何在Excel工作表中仅搜索和编辑“日期类型”单元格

i have this code

我有这个代码

Sub fill()
  Dim rg As Range
  Set rg = Range("a1")
  Set rg = Range(rg, Cells(ActiveSheet.UsedRange.Row + ActiveSheet.UsedRange.Rows.Count - 1, rg.Column))
  On Error Resume Next
  Set rg = rg.SpecialCells(xlCellTypeBlanks)
  On Error GoTo 0
  If Not rg Is Nothing Then
    rg.Value = "1/1/2020"
  End If
End Sub
Sub fill()
  Dim rg