The 2015 Post-Doc Interview Thread has a list of some dates from last year which could give us an idea of when to expect to hear this year. It's hard waiting but it looks like most aren't until the end of December/beginning of January.
http://forums.studentdoctor.net/threads/2015-post-doc-interview-thread.1114766/
http://forums.studentdoctor.net/threads/2015-post-doc-interview-thread.1114766/