If you are thinking of applying for a visa then you should lodge your Student Visa Application at least 6 weeks before the start of your course. The immigration department have stated they will always try their best to complete the process in 4 weeks, however, it is not always a guarantee.
The start date of Overseas Student Health Cover (OSHC) should be the day the student intends to arrive in Australia. A common mistake is to arrange OSHC to commence on the first day of their course. Immigration has stated their officers won’t grant a visa if OSHC begins less than one week before course commencement. For students applying in Australia make sure there are no gaps in coverage.