Britain's Queen Elizabeth II to mark 83rd birthday by working

London: Queen Elizabeth II will mark her 83rd birthday on Tuesday with a low-key day at Windsor Castle, but she won't have the day off work.

The queen's London office says the monarch has nothing special planned or any public engagements scheduled, but she will probably go through the stack of official papers she receives as head of state. She has long done that every day of the year, except Christmas.

A royal salute will be fired at noon in Hyde Park in central London to mark the occasion by the King's Troop of the Royal Horse Artillery.

The queen's birthday is celebrated twice a year, once privately, on her actual birthday, and again with an official national celebration in June.

Marked by a parade known as the "Trooping of the Colour," the celebration this year falls on June 13.