Victoria Day ...

All you need to know about Victoria Day:

Victoria Day (French: Fête de la Reine) is a Canadian holiday celebrated on the last Monday before or on May 24 in honour of both Queen Victoria's birthday and the current reigning Canadian sovereign's birthday.

While Victoria Day is often thought of as a purely Canadian event, it is also celebrated in some parts of Scotland, particularly in Edinburgh and Dundee, as well as in the Cayman Islands, where it is also a public holiday.
The birthday of the monarch was a day for celebration in Canada long before confederation. On May 24, 1854, 5,000 residents of Upper Canada gathered in front of Government House (near present day King and Simcoe Streets, in Toronto) to "give cheers to their queen."[1]

Since 1901, the date of May 24 was known throughout the British Empire as Empire Day. An amendment to the Statutes of Canada in 1952 moved the holiday to the Monday before May 25. However, over the decades the official date of the reigning sovereign's birthday changed through various royal proclamations. For Edward VII, it continued on May 24, but was June 3 for George V, June 23 for Edward VIII (their actual birthdays), and various days between May 20 and June 14 through George VI's reign as King of Canada. From 1953, Empire Day was made the date of Queen Elizabeth II's official birthday in Canada by annual vice-regal proclamation, the link being made permanent in 1957. In 1958 Empire Day was renamed Commonwealth Day.

In 1977 Commonwealth Day was moved to the second Monday in March, but Canadians continued to celebrate Victoria Day in May.

The reigning Canadian monarch has been in Canada for his or her official birthday twice: the first time being on May 20, 1939, when King George VI was on a coast-to-coast tour of Canada and his official birthday was celebrated with a Trooping the Colour ceremony on Parliament Hill. The second time was when Queen Elizabeth II was in Canada from May 17 to May 25, 2005, to mark the centennials of the entries of Saskatchewan and Alberta into Confederation; no events were organized to acknowledge this fact.

In the neighboring United States, Memorial Day is observed on the last Monday of May, making it coincide with Victoria Day much of the time. Several Canadian cities hold a parade in honor of the holiday, with the most famous being in the monarch's namesake city of Victoria, British Columbia. This holiday is also often celebrated with fireworks shows.