Section 80 of the Queensland Electoral Act 1992 states that an election must be held on a Saturday; and that the election campaign must run for a minimum of 26 or a maximum of 56 days following the issue of the writs. (en.wikipedia.org)
Five to seven days following the issue of the writs, the electoral roll is closed, which gives voters a final opportunity to enroll or to notify the Electoral Commission of Queensland of any changes in their place of residence. (en.wikipedia.org)
Once the House agrees to a motion for the issue of a writ, the Speaker is required to carry out the House's decision and to issue his warrant for the by - election. (bbc.co.uk)