A media release from the organisers said the date had been extended to give more people a chance to make a submission. A large number of high-quality proposals had already been received.
The conference is scheduled to be held at the Australian National University in Canberra from January 28 to February 2 next year.
The two members of the talks committee, Mary Gardiner and Michael Davies, endorsed the provision of an extra fortnight, saying they wanted anyone with an idea they were enthusiastic about to have a chance to make a submission.
The LCA, which has been predominantly known for its technical content, broadened its horizons a few years ago to include a broader range of talks.