Prime Minister Justin Trudeau announced Thursday that “the next few days will be a period of mourning for Canadians, as they will be for all citizens of the Commonwealth.” Flags at all federal government buildings – including Canada’s diplomatic buildings abroad – were flown at half-staff Thursday and will remain at half-staff until the day of the queen’s funeral. Many landmarks and buildings across Canada, including the Parliament and Senate buildings, will also be lit up in a royal blue hue each evening from sunset to midnight during the mourning period. The prime minister said this period of mourning will end with a day of national mourning when an official memorial service will be held for her death. This memorial service is to be held at Christ Church Cathedral in Ottawa on the same day as the Queen’s funeral at Westminster Abbey. The time and date of the late Queen’s state funeral have not yet been confirmed by Buckingham Palace, but according to the “Operation London Bridge” plans that have been in place for years, her funeral is expected to take place around 10 days after her death. . . “Operation London Bridge” also states that in the UK, the day of the Queen’s funeral should be treated as a public holiday unless the funeral takes place on a weekend. According to the Government of Canada’s Manual of Official Procedure, the federal government may also decide to observe the national day of mourning as a holiday, but the feds have not indicated they intend to do so. Canada’s national commemoration will begin with a parade in Ottawa featuring the Canadian Armed Forces and the RCMP. There will also be a 96-gun salute — with one round representing each year of Queen Elizabeth II’s life. CF-18 fighter jets will fly over Christ Church Cathedral and Parliament Hill to mark the end of the ceremony. Guests at the invitation-only ceremony in Ottawa will include government officials, foreign dignitaries and “representatives of organizations with which Her Majesty has had a close relationship.” The ceremony will also be streamed live for the public. The House of Commons was adjourned for the summer at the time of the Queen’s death, but if Parliament had been in session, the handbook says the prime minister could suspend parliament out of respect. Although the handbook states that MPs have in the past taken new oaths after the death of the sovereign, there is no legal requirement for them to do so. House Speaker Anthony Rota said in a statement Thursday that lawmakers “will not need to renew the oath of allegiance” since their existing oath “automatically extends to our new sovereign.” Some Canadians may choose to wear black armbands during the mourning period. The Alberta government says wearing a black armband, along with a black tie and dark clothing, is “a sign of respect and a way to formally mourn the passing of a person of state importance.” Some municipalities, such as the City of Ottawa, have also distributed black ribbon pins. The federal government, as well as provincial and municipal governments across the country, have invited Canadians to sign books of condolence. As of Friday, more than 18,000 Canadians have signed the federal government’s online book of condolences. On Saturday morning there will also be a ceremony to announce the legacy of King Charles III at the Rideau Hall. With files from CTV News’ Rachel Aiello and CTV News Ottawa