Queen Elizabeth II passed away on Thursday hours after Buckingham Palace released a statement saying that she was being kept comfortable under medical observation.
Last year, the plans for the first 10 days after her death, codenamed Operation London Bridge, were revealed and laid out the proceedings for the first ten days after her death including Operation Spring Tide - the plans for Charles's accession to the throne.
Thursday, the day of the queen's death, is D-Day, with each day following being referred to as D+1, D+2...
D-Day
In the hours following the queen's death, calls were made to inform Prime Minister Liz Truss, the cabinet secretary and a number of the most senior ministers and officials. Truss was informed by the queen's secretary.
The royal household issued an official notification to deliver the news to the public.
The ministers and civil servants received an email, and upon receiving the email, the flag at Whitehall was lowered to half-mast.
The UK parliament will adjourn following a statement made by Truss shortly after the queen's death was announced. All other government officials were not allowed to make statements until the Truss had.
The royal family's website was changed to a black holding page with a statement confirming the news of the queen's passing, and the UK government website now shows a black banner at the top with the queen's name and dates of birth and death. All governmental social media pages are expected to change their profile pictures to their crests and also display a black banner. Only essential content will be published and retweets will have to be cleared with the government head of communications.
The royal family will announce the time of the funeral, which will probably be ten days after Thursday.
A gun salute will take place at all saluting stations, while Truss and Prince Charles hold an audience, and Charles will deliver a broadcast speech to the nation.
D-Day+1
At 10 AM the Accession Council will convene at St. James Palace to name Charles the new king.
Parliament will formulate a message of condolences, with all other parliamentary activity being suspended until after the funeral, and MPs will give tributes in the House of Commons.
At 3:30 PM, Truss, the cabinet and Charles will meet.
D-Day+2
Since the queen died in Balmoral, her coffin containing her body will be transferred to Buckingham Palace.
There were two possibilities for how to transport the queen: either Operation Unicorn which sees her coffin delivered by royal train, or if Operation Unicorn is not possible, Operation Overstudy will be activated, and she will be flown back to London.
D-Day+3
In the morning, Charles will receive official condolences from Westminister Hall, followed by him departing for a tour of the UK in the afternoon, beginning with the Scottish parliament.
D-Day+4
Charles will arrive in Northern Ireland and will be met with official condolences from Hillsborough Castle and a service in Belfast.
Back in London the procession of the coffin to the Palace of Westminister, Operation Lion, will be rehearsed.
D-Day+5
Operation Lion will take place with a service in Westminister Hall upon the coffin's arrival.
D-Day+6 - D-Day+9
In Operation Feather, the queen's coffin will lie in the Palace of Westminister for three days. The palace will be open to the public for 23 hours a day, and tickets will be issued to VIPs to ensure them a slot.
A rehearsal for the funeral will take place on D-Day+6.
On D-Day+7, Charles will go to Wales to receive official condolences from the Welsh parliament and attend a service at Liandaff Cathedral.
The Foreign Ministry will be charged with the task of arranging the arrivals of foreign leaders and VIPs.
The Home Office will be responsible for security.
The Department for Transport will handle great numbers of citizens making their way to London.
D-Day+10
The state funeral will be held at Westminister Abbey with two minutes' silence at noon. The day will be declared a "Day of National Mourning". The queen will be buried in the King George VI Memorial Chapel.