The German Rail website is now booking through Dec. 2016.
Right now booking is allowed 180 days in advance. That's still a huge change from this spring when it was 90 days.
Earlier this year I was faced with buying tickets from Venice to Innsbruck. The German, Austrian, and Italian websites offered their limited discounted fares at different times: Austrian rail 180 days out, Italian rail 120 days out, and German rail 90 days out. Not knowing that Austrian rail offered their tickets so far in advance I missed the cheapest 29 euro tickets and bought the 39 euro fares about 5 months in advance. When trenitalia came on line 4 months out the cheapest tickets they offered were 55 euros. But when bahn.com came online 3 months out the 29 euro fares were offered once again.