So tomorrow's the day everyone puts up their Christmas tree, right? December 1. It's tradition. It is bad luck on your house if your tree is already up.
Actually, no, there is no real rule except the rule you grew up with.
Monash University Professor Gary Bouma, a sociologist who specialises in religious diversity, says families and individuals abide by the traditions of their childhood Christmases.
"It really is what you grew up with," Professor Bouma said. Although "for some of us it is also when you have the time to throw the thing up".
He said the tradition of not putting up a tree before December 1 is a strong one in Australia but not for all.
Many Christians will only put up decorations on the night before Christmas Eve and never during Advent, the period that includes the four Sundays before Christmas Day. This year the first Sunday of Advent fell on November 29.
"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.
In Britain, Professor Bouma said "Christmas was illegal [in] the time of Cromwell". And there were no trees involved in the celebration until the 19th century
He said the tree was unknown in Britain (and Australia too) until Queen Victoria's husband, the German-born Prince Albert, brought it to the masses and periodicals, such as 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 3, no doubt giving everyone the right to do the same.
If there's a lack of a hard and fast rule about when the tree goes up there's more certainty about when it should be taken down. But only a little more.
For some, the tree must come down by the feast of Epiphany - January 6 - when the three kings are said to have arrived.
What exactly happens if you don't isn't clear with some saying hobgoblins will come to wreck your house for a year if you don't.
"There is 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," Professor Bouma 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 tradition of taking down trees in Australia 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 with Australian fresh Christmas trees, which grew under drier conditions.
"They are bad enough when they are new and full of juice but they dry out and become [a] tinderbox," he said.
Professor Bouma said the good thing about the dispute about when Christmas trees should go up or come down made for lively conversations.
"I don't want to complain about Christmas tradition crossing civilisations," Professor Bouma said.
People will have disputes about local variations and this enriches conversations and traditions that families find terribly important."