It's the Queen's official birthday this week – but when is her actual birthday? 

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.

But why does the Queen have two birthdays, and how does she celebrate them?

The Argus: The royal family on the balcony for Trooping the Colour in 2018The royal family on the balcony for Trooping the Colour in 2018

When is the Queen's birthday?

Queen Elizabeth II celebrates her actual birthday on April 21.

Her actual birthday is normally a private affair but usually the occasion is marked publicly by gun salutes in central London at midday, 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.

This year, the Queen turned 95 just days after the funeral of her husband of 73 years.

She spent the day at Windsor Castle during a period of royal mourning, the palace said.

The queen marked her last big birthday, her 90th, on the official birthday in June 2016, with a big street party near Buckingham Palace for guests from charities of which she is patron. 

Why does the Queen have a second birthday?

A second birthday is arranged to mark the date if a Sovereign's actual birthday does not fall in the summer months.

This is to ensure that there is the greatest likelihood of good weather for the parade, also known as Trooping the Colour.

The Argus: Queen Elizabeth II Queen Elizabeth II

Like the Queen, King Edward VII was not was born in the summer, so whilst he celebrated his actual birthday on 9 November, his official birthday was marked throughout his reign in May or June in the hopes that the weather would be good for his Birthday Parade.

What is Trooping the Colour?

Trooping the Colour is a parade in central London featuring the Household Cavalry.

Around 1,400 soldiers, 200 horses and 400 musicians usually take part in the parade.

They march from Buckingham Palace down The Mall towards Downing Street.

The Royal Family then follow in horse-drawn carriages or on horseback.

The parade finishes with the Queen and her family standing on the balcony at Buckingham Palace, waving to the crowds below whilst the Red Arrows do a fly-past.

What is the plan this year?

Buckingham Palace said the Duke of Kent will serve as Her Majesty's "plus one" for the annual celebration on Saturday.

The pair are related through their fathers, Prince George, the former Duke of Kent, and King George VI, who died when the monarch was just 25.

The Argus: Queen Elizabeth ll and the Duke of Edinburgh arriving to a celebration in 2015 Queen Elizabeth ll and the Duke of Edinburgh arriving to a celebration in 2015

Edward previously filled in for Philip at the parade in 2013 when he was in hospital after abdomen surgery.

The display will be held in Windsor Castle's quadrangle, and will be similar to last year's event at the Berkshire residence dubbed "mini trooping".

Covid guidelines will be followed during the event which will incorporate many elements of the annual Queen's Birthday Parade.

It will feature troops who have played an integral role in the NHS' Covid-19 response and those who have been serving on military operations overseas.

The announcement comes days after the Palace confirmed the dates and full itinerary for the celebrations to mark the Queen's Platinum Jubilee next summer, to be held over an extra four-day Bank Holiday.

Her Majesty will celebrate 70 years on the throne in June 2022 and the 'once-in-a-generation' occurrence will see Britain afforded an extra two days off work.

The monarch will be 96 by the time the landmark is reached, making her the first sovereign to reign for seven decades.