The self-lodgement tax deadline falls on 31 October every year, closing the four-month window that opened on 1 July. 22 October 2029 falls inside October, the final month of that window, in the fourth calendar quarter of 2029, with the deadline drawing closer as the month progresses.
Monday 22 October 2029 is the first working day of its week. Any bill, deadline or rostered task set for the preceding Saturday or Sunday moves to this date under standard business-day rules, and the working-day count above treats it as day one of a fresh five-day working stretch that runs through to Friday, before the weekend resets the cycle again.
2029 has 365 days on the calendar. Leap years add a single extra day to February, giving those years 366 days instead of 365 and shifting the day-of-year number for every date from March onward by one compared with an ordinary year. This is the only irregularity in the length of the Australian calendar year.