It is the Queen's birthday on Wednesday 21 April - this year she turns 95, but she also has another one later in the year.
The Queen has two birthdays - her real one - on 21 April, as she was born on 21 April 1926.
Then a second one - the official celebration - on the second Saturday of June.
So why does the Queen have two birthdays, and how does she celebrate them?
In the past, official celebrations to mark a King or Queen's birthday in the UK have been held on a day that isn't their actual birthday.
The Queen's great-grandfather, Edward VII, who was King from 1901 to 1910 was born in November, which is not known in the UK for its good weather.
But he wanted it to be possible to have a big public celebration - and November wasn't the time do it.
So, given that his actual birthday wouldn't be a good time of year for a birthday parade, he decided to combine it with an annual military parade in the summer, when the weather would hopefully be nice.
The Queen usually spends her actual birthday with her family.
There is usually a 41-gun salute in Hyde Park, a 21-gun salute in Windsor Great Park and a 62-gun salute at the Tower of London on 21 April but they have been cancelled this year because of the coronavirus pandemic.
The Queen and the Royal Family are still in mourning following the death of Prince Philip, aged 99, so celebrations will be smaller this year.
The Trooping the Colour parade marks her official birthday and usually takes place in June, but that has also been cancelled this year.
It is only the third time in her reign that the parade has not gone ahead.
Trooping the Colour has marked the official birthday of the British monarch for more than 260 years.
More than 1400 soldiers, 200 horses and 400 musicians usually take part in the event, so it's quite a spectacle!
Lots of members of the public waving flags and wearing Union Jacks normally fill the Mall outside Buckingham Palace to watch it.
On the day, normally a big parade starts at the Queen's official residence - Buckingham Palace - before moving along the Mall to Horse Guards Parade at Whitehall, near to Downing Street, and then back again.
Then it's traditional for the royal family to travel down the Mall as part of the ceremony, and gather on Buckingham Palace's balcony to greet well-wishers and watch RAF planes perform an aerial display for the occasion.