如何在 Excel 中计算 1900 年 1 月 1 日之前的年龄？

Public Function AgeFunc(SDate As Variant, EDate As Variant) As Long
'UpdatebyExtendOffice20160429
    Dim xSMonth As Integer
    Dim xSDay As Integer
    Dim xSYear As Integer
    Dim xEMonth As Integer
    Dim xEDay As Integer
    Dim xEYear As Integer
    Dim xAge As Integer
    If Not GetDate(SDate, xSYear, xSMonth, xSDay) Then
        AgeFunc = "Invalid Date"
        Exit Function
    End If
    If Not GetDate(EDate, xEYear, xEMonth, xEDay) Then
        AgeFunc = "Invalid Date"
        Exit Function
    End If
    xAge = xEYear - xSYear
    If xSMonth > xEMonth Then
        xAge = xAge - 1
    ElseIf xSMonth = xEMonth Then
        If xSDay > xEDay Then xAge = xAge - 1
    End If
    If xAge < 0 Then
        AgeFunc = "Invalid Date"
    Else
        AgeFunc = xAge
    End If
End Function

Private Function GetDate(ByVal DateStr As String, Y As Integer, M As Integer, D As Integer) As Boolean
    Dim I As Long
    Dim K As Long
    Y = 0
    M = 0
    D = 0
    GetDate = True
    On Error Resume Next
    I = InStr(1, DateStr, "/")
    M = CLng(Left(DateStr, I - 1))
    D = CLng(Mid(DateStr, I + 1, InStr(I + 1, DateStr, "/") - I - 1))
    Y = CLng(Right(DateStr, Len(DateStr) - InStrRev(DateStr, "/")))
    If M < 1 Or M > 12 Or D < 1 Or D > 31 Or Y < 1 Then
        GetDate = False
    End If
End Function