recurringDay format

Hi,

In Schema part 2:  [3.3.32 RecurringDay]
http://www.w3.org/TR/xmlschema-2/#recurringDay, it says
The lexical representation for recurringDay is the left truncated
lexical representation for
date: ---DD . No other formats are allowed.

But in part 0: [2.3 Simple Types]
http://www.w3.org/TR/xmlschema-0/#CreatDt, it has
an example of recurringDay of "----31".

Is the format "----DD'' and  "---DD" a typo?

Thanks in advance!
Jing