Most Canadians will enjoy a day off Monday for Victoria Day. Known informally as May two-four, almost all of Canada (sorry Nova Scotia, New Brunswick, Newfoundland and Labrador, and Prince Edward Island) gets a day to relax and welcome the unofficial start of summer. Here’s everything you need to know about the history of the holiday and interesting facts.

What is the history behind Victoria Day? Canada first began celebrating Victoria Day in 1845 and it was officially established as a national holiday in 1901 in honor of Queen Victoria’s birthday on May 24. The day honors the British monarch who reigned over Canadian unity with the Confederation of 1867 and is meant to help bridge differences between English and French Canadians. In case you forget the day, here is an old rhyme to help remember: “The 24th of May is the queen’s birthday. If we don’t get a holiday, we’ll all run away.”

In Quebec the holiday became known as National Patriotes Day in 2002 to honor the francophone political party.

While the holiday remained a low-key affair in its early years, it has become known as an informal start to summer with parades and firework displays with the nickname “May long weekend.” Parts of Scotland also celebrate the holiday.

Why does the holiday fall on different days? Canada’s Parliament declared in 1952 that Victoria Day would always fall on the Monday before May 24, so some years that can be more than a week earlier.

What are the disasters, legends and famous events associated with the holiday? One of Canada’s worst disasters took place on Victoria Day in 1881. The “Victoria” steamship sank in London, Ontario, killing 182 people. The overcapacity boat was taking people downtown from celebrations for the holiday.

The holiday also has a strange ghost story tied to another tragic incident. In 1896 a streetcar in Victoria was overcrowded, and the bridge over which it was traveling collapsed, killing 55 people. Legend has it a red light is visible under the bridge from time to time, and no one knows its origin.

The holiday is also tied with a historic event. In 1916 women gained the right to vote in federal elections on Victoria Day.