And why the date changes annually...
The Queen has two birthdays a year, celebrating on the actual day she was born, April 21st, and then also on her Official Birthday, taking place in June.
While it’s hard enough to keep track of two birthdays, it gets even more confusing for the Queen as it turns out the date of her official birthday changes every year.
It turns out that the tradition of a monarch having two birthdays is centuries-old, dating back to 1748. The reigning monarch at the time, King George II, supposedly found his November birthday too cold to celebrate publicly so he chose to have another birthday in June when he could officially celebrate the date, later combining it with the annual Trooping the Colour parade.
While the tradition is still being practised, the annual day has been moved, with the official birthday historically being celebrated on a Thursday. During Queen Elizabeth II’s reign however, it has been changed to be held on a Saturday, allowing members of the public to attend the parade.
With the official date held each June on a Saturday, usually the second of the month, the date changes each year and Queen Elizabeth has a different birthday each year.
Happy Birthday to Queen Elizabeth again.