我正在使用VBA DateSerial函数分隔字符串中的日期，但是当字符串中的年份为'1000'时，Excel Ends Sub会出现。 我究竟做错了什么？

Question

I am using the VBA DateSerial function to separate dates in a string, and populate them on another worksheet but Excel Ends Sub when the year in string is '1000'.

Here is an example:

string data:
2012-01-012012-03-01
2013-01-012013-03-01
1000-01-011000-01-01

VBA code:
Private Sub Worksheet_Change(ByVal Target As Range)
    If Not Intersect(Target, Columns(1)) Is Nothing Then
        On Error GoTo Safe_Exit
        Application.EnableEvents = False
        Dim rng As Range, str As String, rw As Long
        For Each rng In Intersect(Target, Columns(1))
            str = rng.Value
            If Len(str) >= 8 Then
                With Sheet2
                    rw = .Cells(Rows.Count, 1).End(xlUp).Offset(1, 0).Row
                    .Cells(rw, 1) = DateSerial(Left(str,4), Mid(str, 6, 2), Mid(str, 9, 2)) 
                    .Cells(rw, 2) = DateSerial(Mid(str, 11, 4), Mid(str, 16, 2), Mid(str, 19, 2)) 
                End With
          End If
        Next rng
    End If
Safe_Exit:
    Application.EnableEvents = True
End Sub

No matter how many strings I paste into the first worksheet, the dates will appear on the second sheet only until a date with the year 1000. What am I doing wrong?

Answer 1

Excel bases dates as number of days since midnight 30 December 1899 and does not except negative dates.

Even though it appears that you can enter dates prior to Jan 1, 1900, if you notice that they will be left-aligned. This indicates that they have been accepted as string values and not a date.

You could modify your code to set a String value instead. A valid date as a string will automatically be converted to a date. .Cells(rw, 1) = Cstr(DateSerial(Left(str,4), Mid(str, 6, 2), Mid(str, 9, 2)))

Note that 1/1/1904 could also be the minimum if the 1904 Date option is selected.