The winter solstice falls in the third week of June every year, the shortest day and longest night on the Australian calendar. 20 June 2027 sits close to this turning point, after which daylight hours slowly lengthen again toward summer, even though winter continues for two more months, through July and August.
A public holiday that falls on a Sunday sits inside the weekend rather than beside it, and whether a substitute day off applies to the following Monday depends on the specific holiday and the state. Sunday 20 June 2027 falls on this day of the week, at the close of the weekend, immediately before the working week resumes.
A public holiday that falls on a Monday or a Friday produces a three-day weekend without using any annual leave, which is why long-weekend planning around 20 June 2027 depends on which day of the week the nearest public holiday falls on. A midweek holiday delivers no such automatic extension, though many workers bridge it with a single day of leave.