Just days after observing a day of mourning for the Queen, Western Australians will have another day off — celebrating the new King's birthday.
The western state is one of the first to change the holiday name.
But when will the other state's change the name, why is it held on different days in different locations and when is King Charles III's actual birthday.?
Here's what you need to know.
When does the Queen's Birthday Holiday change to the King?
Western Australia and Victoria have already updated the public holiday name to the King's Birthday.
In Queensland, ACT and Tasmania, the holiday is officially titled the Birthday of the Sovereign and more informally known as the Queen's birthday.
Northern Territory and South Australia have scheduled holidays in their respective acts for the second Monday in June with no official title for the date — however both still refer to the Queen's Birthday on their official government websites.
New South Wales public holidays schedule is outlined in the Public Holiday Act (2010), including the Queen's Birthday, meaning an amendment will need to be made to the act to change the title.
It is possible the holiday name may not change until after King Charles III's coronation, as is what happened with his mother.
Does the date stay the same?
Given the date has been the same since 1938 it's unlikely the date will be changed. However, as the states declare the dates, it's possible.
King George VI had a public holiday wrapped into his Coronation Day on May 12, and similarly Queen Elizabeth II had a joint birthday and coronation on June 2.
So depending on what time of year Charles has his coronation, Australians might have the public holiday moved to a different time of year.
Why do different states have different dates?
All states but Queensland and Western Australia celebrate the date in June.
WA observes Western Australia Day, formerly known as Foundation Day, on the first Monday of June.
The holiday marks the day when the first European settlers, under the command of Captain James Stirling RN, Lieutenant Governor, arrived from Britain to settle the Swan River colony.
The King's Birthday is typically the last week of September or the first week of October — depending on when the Perth Show holiday falls.
For this reason WA local governments are also allowed to choose an alternate date for the public holiday to coincide with their local show holiday.
In Queensland the Queen's birthday was initially moved in 2012 to October for a better spread of public holidays.
The date was changed back to June in a change of state government in 2013 and Labour Day was moved to October.
When the government changed again in 2015 the holidays were switched, moving Labour Day back to May and the Queen's Birthday back to October where it remains.
When are Queen's/King's real birthdays?
The Queen's actual birthday was April 21, 1926.
King Charles III was born on November 14, 1948.
However, the June date was decided in 1938 to mark King George VI's birthday — despite that date being December 14, 1895.
The June date actually falls closest to King George V, Queen Elizabeth II's grandfather, who was born June 3, 1865.
Will there be a public holiday for the coronation?
When Queen Elizabeth II had her coronation, the event was combined with the Queen's Birthday public holiday on June 2, similarly to her father King George VI on May 12.
In the United Kingdom Britons will have the day off for the coronation.
However there is no confirmed date for the event, and it may be a while off.
Queen Elizabeth II's coronation was more than a year after her father's death and her ascension.
It's not known yet whether Australians will receive an extra holiday.
Who decides what days are public holidays?
The state and territory governments are responsible for declaring the public holidays.
Although there are some national ones which occur on the same date across the country, such as Christmas or Anzac day, some states have their own holidays - such as the previously mentioned Western Australia Day.
Victoria's special public holiday for the AFL grand final means Victorians will have an extra long weekend combined with the Queen's funeral holiday. Victoria also has an extra public holiday for Melbourne Cup day.
In South Australia every Sunday is legally a public holiday. However, there are award and enterprise agreements which override the act when it comes to pay.
SA also recognises National Volunteers Day on the same day as the Queen's Birthday.
Northern Territory also recognise Picnic Day in the first week of August.
Across each state and territory a number an extra date is typically observed to coincide with the local agricultural shows.
