timrwood/moment — pull request #874 by jojosati (2013-07-03 17:32:47+00:00)
Title: Buddist Calendar / Thai solar Calendar support with format code BB, BBBB

Buddist Calendar / Thai solar Calendar support with format code BB, BBBB
THAI YEAR (BE.) is +543 years greater than AD. (that's all)
http://en.wikipedia.org/wiki/Thai_solar_calendar

Microsoft Excel 2003 and later uses b or B for Buddhist Calendar
http://office.microsoft.com/en-us/excel-help/format-dates-using-alternate-calendars-HP005262656.aspx