less than a minute:
"Section 13 of the Constitution of Australia requires that in half-Senate elections the election of State senators must take place within one year before the places become vacant. As the terms of half the senators end on 30 June 2017, the writs for a half-Senate election cannot be issued earlier than 1 July 2016, and the earliest possible date for a simultaneous House/half-Senate election is 6 August 2016"
