When should you put up your Christmas tree?
December 1 is the day when everyone is allowed to put up their Christmas tree. It's tradition, right? Bad luck to go early?
The Obamas already have their tree, but won't flip the lights switch until this week. If you went by the timing of supermarkets, your tree would have been up for months already.
Actually, the rule is, there is no rule - only the rule you grew up with.
Monash University Professor Gary Bouma, sociologist on religious diversity, says families and individuals abide by the traditions of Christmas that they grew up with as a child at home.
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"It really is what you grew up with, but for some of us it is also when you have the time to throw the thing up," Professor Bouma said.
He said the tradition of resisting putting up the tree before December 1 is a strong one, but not everyone abides by it.
Many Christians will only put up decorations on the night before Christmas Eve and never during Advent, which began on Sunday, November 27 this year.
"Traditionally, for many Christians, Advent is a time of fasting - none of this extra food that we do normally in Australia - and you can't sing Christmas carols," Professor Bouma said.
"But in Australia I've noticed that the partying starts about now," he said.
He said the Christmas tree was essentially unknown in Britain until Prince Albert, a German, brought it to the masses. At the time, periodicals like the Illustrated London News began describing the royal tree in intricate detail.
At the White House, President Barak Obama and First Lady Michelle Obama will "flip the switch" on December 1, but took delivery of their huge tree on November 25, giving others the right to start thinking about doing the same. It isn't always on December 1 though; last year it was December 3 - making it the first Thursday in December.
So when should the tree that takes up a lot of space in your lounge room come down?
For some, the tree must come down by January 6 - or the Epiphany when the three kings are said to have arrived. What exactly happens if you don't pull the tree down by then isn't clear. Some say hobgoblins will come to wreck your house for an entire year if you don't pull it down by then.
"There is a large tradition of Christmas trees coming down by the Epiphany, but that is not true in France. In France, it starts a month of celebrations and eating," he said.
The Epiphany heralds the arrival of the gallette de rois - the cake of kings - a pastry and marzipan affair baked in rings.
Professor Bouma said the local tradition of pulling down trees by January 6 might be because of the warmer climate. He said in Europe and America, the trees would often stay up well after Christmas, until they dried out and became a fire hazard. He said those trees were heavily hydrated compared to fresh Christmas trees in Australia, which grew under drier conditions.
"They are bad enough when they are new and full of juice but they dry out and become tinderbox," he said.
For others, it is when they get tired of the cat attacking the tree and pulling off the decorations.
Professor Bouma said the good thing about the great Christmas tree dispute is that it makes for lively conversations.
"I don't want to complain about Christmas tradition crossing civilisations. People will have disputes about local variations and this enriches conversations and traditions that families find terribly important," Professor Bouma said.