1st July is Canada Day. It celebrates the anniversary of the July 1, 1867, the effective date of the Constitution Act, 1867 (then called the British North America Act, 1867), which united the three separate colonies of the Province of Canada, Nova Scotia and New Brunswick into a single Dominion within the British Empire called Canada. Thanks to wiki here. The 150th anniversary in 2017 was a big event in Trafalgar Square:
2018 was more “personal”. A popular place to meet up is the Maple Leaf pub in Maiden Lane, Covent Garden. On map here.