When the Queen gets off the train at King's Lynn station each December and heads to her estate at Sandringham, you know Christmas is well and truly on its way.
But that regular festive tradition now looks unlikely to take place this year, while the monarch's entire trip to Norfolk this winter remains in doubt because of the recent surge in Covid cases.
Officials say a decision has yet to be made on the Queen's yuletide plans, but have indicated that her customary arrival by train will almost certainly not take place. Instead, a journey by helicopter is considered more likely.
On Monday, one official said that a decision on whether she would spend Christmas at Sandringham would be made "within the next day or so".
She is currently at Windsor Castle and it has been reported that she missed a church service there over the weekend as a precautionary move to try to ensure her traditional Sandringham celebrations could go ahead.
Pre-pandemic, she would host her children, grandchildren and great grandchildren at her Norfolk retreat for Christmas with all the trimmings.
In recent years, she would catch a scheduled Great Northern train from London King's Cross to Lynn a few days before December 25.
After being greeted by the station master, she would leave via her own special exit, complete with Royal coat of arms, before getting into the 4x4 which would take her the final 10 miles to Sandringham.
On arrival, she would begin overseeing preparations at the house, including choosing a Christmas tree from her nearby saw mills and agreeing menus.
Family members would arrive on Christmas Eve, in reverse order of seniority.
If she does spend Christmas at Sandringham, one question will clearly be whether the Queen will host the usual gathering of around 30 people or a smaller party.
While the government has not so far set limits on how many should attend family get-togethers over Christmas, its chief medical adviser Prof Chris Whitty has said people should think carefully before attending parties and not mix with anyone they don't have to.
The weekend reports that she pulled out of a church service to avoid any risk of compromising her family's Christmas plans came after a Windsor party for members of her extended family who would not be joining her in Norfolk was also cancelled.
The Queen is said to be determined to spend her first Christmas without her husband of 73 years, Prince Philip at Sandringham. The Duke of Edinburgh passed away at the age of 99 in April.
If she does, one festive tradition is likely to go by the board. Officials have reportedly already decided the public will not be allowed into the grounds at Sandringham on Christmas Day.
Thousands usually gather to greet the Queen and members of her family when they attend morning service at Sandringham Church.
While the Queen usually arrives in her Bentley, family members walk the short distance from Sandringham House, along paths lined with well-wishers.
This year, the iron gates by the war memorial are likely to be locked and people turned away to reduce the risk of spreading the virus.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here