Officially Victoria Day was established in 1845 to honour Queen Victoria. It fell on May 24th each year until 1952 when the Canadian Government declared that it would fall on the first Monday before May 25th.
It is unofficially considered to be the beginning of summer and many Canadians refer to it as “May two four”. This is likely in acknowledgement of the standard sized case of beer containing 24 bottles or cans, known as a “two four”, and is often the beverage of choice on this holiday.