启动 Excel。 查看要使用 函数的工作表。

按 Alt+F11 切换到 Visual Basic 编辑器。

在“插入”菜单上，单击“模块”。

在模块中键入以下代码：

' This is the initial function. It takes in a start date and an end date.
Public Function AgeFunc(stdate As Variant, endate As Variant)
    ' Dim our variables.
    Dim stvar As String
    Dim stmon As String
    Dim stday As String
    Dim styr As String
    Dim endvar As String
    Dim endmon As String
    Dim endday As String
    Dim endyr As String
    Dim stmonf As Integer
    Dim stdayf As Integer
    Dim styrf As Integer
    Dim endmonf As Integer
    Dim enddayf As Integer
    Dim endyrf As Integer
    Dim years As Integer
    ' This variable will be used to modify string length.
    Dim fx As Integer
    fx = 0
    ' Calls custom function sfunc which runs the Search worksheet function
    ' and returns the results.
    ' Searches for the first "/" sign in the start date.
    stvar = sfunc("/", stdate)
    ' Parse the month and day from the start date.
    stmon = Left(stdate, sfunc("/", stdate) - 1)
    stday = Mid(stdate, stvar + 1, sfunc("/", stdate, sfunc("/", stdate) + 1) - stvar - 1)
    ' Check the length of the day and month strings and modify the string 
    ' length variable.
    If Len(stday) = 1 Then fx = fx + 1
    If Len(stmon) = 2 Then fx = fx + 1
    ' Parse the year, using information from the string length variable.
    styr = Right(stdate, Len(stdate) - (sfunc("/", stdate) + 1) - stvar + fx)
    ' Change the text values we obtained to integers for calculation 
    ' purposes.
    stmonf = CInt(stmon)
    stdayf = CInt(stday)
    styrf = CInt(styr)
    ' Check for valid date entries.
    If stmonf < 1 Or stmonf > 12 Or stdayf < 1 Or stdayf > 31 Or styrf < 1 Then
        AgeFunc = "Invalid Date"
        Exit Function
    End If
    ' Reset the string length variable.
    fx = 0
    ' Parse the first "/" sign from the end date.
    endvar = sfunc("/", endate)
   ' Parse the month and day from the end date.
    endmon = Left(endate, sfunc("/", endate) - 1)
    endday = Mid(endate, endvar + 1, sfunc("/", endate, sfunc("/", endate) + 1) - endvar - 1)
    ' Check the length of the day and month strings and modify the string 
    ' length variable.
    If Len(endday) = 1 Then fx = fx + 1
    If Len(endmon) = 2 Then fx = fx + 1
    ' Parse the year, using information from the string length variable.
    endyr = Right(endate, Len(endate) - (sfunc("/", endate) + 1) - endvar + fx)
    ' Change the text values we obtained to integers for calculation 
    ' purposes.
    endmonf = CInt(endmon)
    enddayf = CInt(endday)
    endyrf = CInt(endyr)
    ' Check for valid date entries.
    If endmonf < 1 Or endmonf > 12 Or enddayf < 1 Or enddayf > 31 Or endyrf < 1 Then
        AgeFunc = "Invalid Date"
        Exit Function
    End If
    ' Determine the initial number of years by subtracting the first and 
    ' second year.
    years = endyrf - styrf
    ' Look at the month and day values to make sure a full year has passed. 
    If stmonf > endmonf Then
        years = years - 1
    End If
If stmonf = endmonf And stdayf > enddayf Then
        years = years - 1
    End If
    ' Make sure that we are not returning a negative number and, if not, 
    ' return the years.
    If years < 0 Then
        AgeFunc = "Invalid Date"
        AgeFunc = years
    End If
End Function
' This is a second function that the first will call.
' It runs the Search worksheet function with arguments passed from AgeFunc.
' It is used so that the code is easier to read.
Public Function sfunc(x As Variant, y As Variant, Optional z As Variant)
    sfunc = Application.WorksheetFunction.Search(x, y, z)
End Function
保存文件。
键入以下数据：
 A1 01/01/1887
 A2 02/02/1945
在单元格 A3 中，输入以下公式：
=AgeFunc(startdate,enddate)
              startdate 是对 A1) 第一个日期 (单元格引用，enddate 是对 A2)  (第二个日期的单元格引用。

结果应为 58。
检查 1900 年 1 月 1 日之前的所有日期是否有效。 Excel 不会检查以文本形式输入的日期。
有关如何使用本文中的示例代码的详细信息，请参阅 如何在 Office 2010 中运行知识库文章中的示例代码。