[excel] Is there a limit on an Excel worksheet's name length?

When I try to set a longish worksheet name using ruby and win32ole with the following code:

require "win32ole"
excel = WIN32OLE.new('Excel.Application')
excel.Visible = 1
puts excel.version
workbook = excel.Workbooks.Add
worksheet1 = workbook.Worksheets.Add
worksheet1.Name = "Pseudopseudohypoparathyroidism" #Length 30, fine
worksheet2 = workbook.Worksheets.Add
worksheet2.Name = "Supercalifragilisticexpialidocious" #Length 34, not fine

I get the following:

12.0
-:9:in `method_missing': (in setting property `Name': ) (WIN32OLERuntimeError)
    OLE error code:800A03EC in Microsoft Office Excel
      You typed an invalid name for a sheet or chart. Make sure that:

 The name that you type does not exceed 31 characters.
 The name does not contain any of the following characters:  :  \  /  ?  *  [  or  ]
 You did not leave the name blank.
    HRESULT error code:0x80020009
      Exception occurred.
        from -:9:in `<main>'

The version 12.0 indicates that I'm running Excel 2007, but it's complaining that the worksheet name is too long. I had a look at Excel 2007 specifications and limits as mentioned in this related answer, and I couldn't find it mentioning any such limit. (Trying to rename a worksheet manually suggests there may be such a limit, however)

Is there a limit, and is it a hard limit or one that can be changed by changing the configuration of Excel?

I use the following vba code where filename is a string containing the filename I want, and Function RemoveSpecialCharactersAndTruncate is defined below:

worksheet1.Name = RemoveSpecialCharactersAndTruncate(filename)

'Function to remove special characters from file before saving

Private Function RemoveSpecialCharactersAndTruncate$(ByVal FormattedString$)
    Dim IllegalCharacterSet$
    Dim i As Integer
'Set of illegal characters
    IllegalCharacterSet$ = "*." & Chr(34) & "//\[]:;|=,"
    'Iterate through illegal characters and replace any instances
    For i = 1 To Len(IllegalCharacterSet) - 1
        FormattedString$ = Replace(FormattedString$, Mid(IllegalCharacterSet, i, 1), "")
    Next
    'Return the value capped at 31 characters (Excel limit)
    RemoveSpecialCharactersAndTruncate$ = Left(FormattedString$, _
                           Application.WorksheetFunction.Min(Len(FormattedString), 31))
End Function

My solution was to use a short nickname (less than 31 characters) and then write the entire name in cell 0.

I just tested a couple paths using Excel 2013 on on Windows 7. I found the overall pathname limit to be 213 and the basename length to be 186. At least the error dialog for exceeding basename length is clear:

And trying to move a not-too-long basename to a too-long-pathname is also very clear:

The pathname error is deceptive, though. Quite unhelpful:

This is a lazy Microsoft restriction. There's no good reason for these arbitrary length limits, but in the end, it’s a real bug in the error dialog.

Renaming a worksheet manually in Excel, you hit a limit of 31 chars, so I'd suggest that that's a hard limit.