Where DateTimeFormat.MonthName[12] is used?

According to MSDN in .Net DateTimeFormat.MonthName should contain exactly 13 elements with 12 element 开发者_JAVA百科should be empty string. What this empty string is used for?

For index 12. Indexes 0--11 are the actual months in, for example, the en-US culture (January, February, etc.). The issue is that some Calendars have thirteen months.

Because in some cultures year consists of 13 months.