Since the original kie refactor november 2012, kie-knowledge isn't build any more (and it can't build).
In the split package refactor april 2013, a new compilation problem was introduced (on top of the existing ones):

This classes's package no longer matches it file location - https://github.com/droolsjbpm/droolsjbpm-knowledge/blob/6.0.0.Beta3/knowledge-api/src/main/java/org/drools/time/Calendar.java