Spring begins on 1 September, and by 18 September 2026 warmer days return across the southern states after the winter months. The AFL finals series runs through September, ahead of the Grand Final that follows in late September or early October, drawing national attention as one of the biggest fixtures on the Australian sporting calendar.
Some employers close early or run a shortened day on Friday, ahead of the weekend that follows. 18 September 2026 falls on this day, the last of the five working days counted in the total shown above for its week, immediately before Saturday and Sunday begin the two-day break most standard working arrangements observe.
Contracts and legal deadlines that specify calendar days count every day from 18 September 2026 including weekends and public holidays, while deadlines specified in working or business days count only the days this page includes in its working-day total. The difference between the two conventions can shift a deadline by several days once weekends and holidays are counted.