You can find information on day count fraction calculations and other conventions in the documentation at http://jfin.org/. jFin also provides full implementations of 10 different day count conventions in Java, it's open source so all of the code is there.

<r>I administer <URL url="http://jfin.org/">http://jfin.org/</URL>, it is currently in beta but passes over 120 unit tests (including some created from examples in ISDA documentation).In order to get the date arithmetic library to production release I need to collate a test pack from many different ...