ThreeTen/threeten-extra — pull request #30 by catull (2014-12-31 00:28:48+00:00)
Title: Enhancement: Add International Fixed chronology

Implemented IFC - chronology for International Fixed calendar, described in http://en.wikipedia.org/wiki/International_Fixed_Calendar.
It is a bit similar to Pax, has the same leap year rule as the Gregorian calendar.
However, it consists of 13 months with each 28 days; leap day is inserted between end of month 6 and beginning of month 7.