What is the timeline for academic job postings in the humanities in Australia?
Universities in Australia take a slightly different approach from those in the US. Rather than recruiting serious academic positions almost exclusively at the assistant professor/level B level and recruiting in cohorts, they tend to advertise positions when they get new funding or when someone leaves, rather than on any particular timeline, and may hire (or cut positions) at any level of seniority. 

If you look at the websites of universities, most of them currently have some academic positions open, with deadlines ranging from tomorrow to the end of July. You just need to be on the lookout for suitable positions in your field. 

That said, the academic semesters in Australia run from about February to June and from about August to November, so it is likely that there are more positions being advertised in May-June and November-December, looking for people who will be ready to teach at the start of the coming semester.

ETA: Here's one for you to look at: http://www.jobs-monash.jxt.net.au/academic-jobs/lecturer-senior-lecturer-in-literary-studies/642748