Australian here, decorations go up in about early December and come down by early January generally; I imagine similar to the US.

Otherwise given there's no snow during that time of year, it's usually celebrated by doing summer things like going to the beach, having a barbie, and generally just a time for families and friends to come together while no-one has work.

Sweden. Some people are having decorations up already but normal is from advent. Christmas is celebrated the eve of the 24th with dinner and Santa visiting in person. Dinner is commonly a Christmas ham and other regional or family traditional dishes. 25th is a slow day when kids are playing with their new toys and the adults are relaxing after the build up until Christmas eve. The evening of the 25th is quite common for young adults that are visiting their family home in a town where they no longer live to go out to the local bars and get shitfaced with people they used to know, possibly air their teenage grudges or crushes and get in a fight or laid depending on the scenario and outcome.

Some of us, in the UK, play Whamageddon which is a concerted effort to get all the way through December up to Christmas Day without hearing ‘Last Christmas’ by Wham.

“I got Whammed in Poundland today!” is a typical cry of dismay for someone who has failed.

Rural Germany. Christmas time still starts in December/1st advent for me, although some houses have wintery decorations up the day they remove the Halloween ones, and the city has made some preparations for the coming Christmas markets today. Christmas markets are where people go buy Glühwein/mulled wine in a Christmassy atmosphere, a hot drink just tastes better in cold weather than in one's house (we drink it there as well, of course, can't enjoy Christmas sober).

Advent traditions include an advent wreath, which is still really Christian in nature, and advent calendar, which has become entirely commercialised around toy brands and chocolate.

The gift giving and the first proper look at the tree is done on Christmas Eve's Evening, after the religious members of the family went to Church. That evening we eat either raclette or hot pot/Chinese fondue, the other meal then a week later at Silvester. We have started to eat a locally sourced Christmas goose on Christmas day recently.

Quebec here. There isn’t much "magic" anymore. Too much too early too soon. It has become pretty much only a cheap commercial stunt.

Some asshole stores annoyingly start decorating early September, most do it in October. And the fucking music blasting non-stop 24/7.

Fuck this shit.

It only sort of counts (I'm Canadian), but my American wife was delighted that everyone puts up their decorations in mid-November (after Remembrance Day on Nov 11). Our Thanksgiving was back in October.

We hit the Christmas Log with sticks to make him poop candy.

UK here, I expect we’re similar to the US except with mince pies and mulled wine, which I understand aren’t really a thing over there. We won’t out our decorations up until December, maybe a week in or so. Shops put them up around mid November once bonfire night is over.

I used to live in Morocco. There wouldn’t be much of it except in the richer areas where they expected Westerners. You might see some stuff up in shops. It was just a normal day to them but it was weird for my first one as we spent Christmas Day in the outdoor swimming pool. One thing I remember that was strange was that they didn’t really understand the timing of it. To me, Christmas Day is like the last day of Christmas, and the rest of Christmas is the build up to it. They saw Christmas Day as the first day of Christmas and I remember a shopping centre advertising all the Christmas events they had starting on Christmas Day, like they thought westerners would be out and about. I guessed it was because they compared it to Aid (Eid in other Arabic countries), when they slaughter a sheep on the first day then spend the rest of the holiday eating it. They also sort of treated a Christmas tree as a New Years tree, and you would see trees and decorations up in March and April still.

UK here. Pretty similar to the US in most respects, I think? But we have Christmas pudding, the ~~queen’s~~ king’s speech on telly, and Boxing Day on the 26th.

My wife is Belgian, so in our house we combine the otherwise conflicting traditions of when to open presents: most stuff gets opened at midnight, in the European fashion, but then we save the smaller ‘stocking filler’ gifts until the morning. Best of both worlds!

New Zealand here. Most of us don't do a lot of decorating, but some people are really into it. My wife has put up a mini-tree already. The big one comes out on December 1st, even though I argue that's too early. We like to have an outdoor BBQ on Christmas Day, as it's generally shorts weather.

BBQs and the beach here in NZ, much the same as .au.

The shops here have just started to decorate in the last week or so. The first houses are starting to put stuff up. We kick off on Dec 1st when we tane the kids to cut down a tree and then do a advent from then to the 23rd. We do our christmas on the 24th and travel to my mums on the 25th and do christmas lunch/dinner ther and stay for at least her birthday (the 26th). Generally do a BBQ and a ham.

Greece here! We put on decorations pretty much when we please, as far as it's before the Christmas eve. The timeline is:

• December 6th, St. Nicholas day: rather than gift giving, this day is attributed to sailors. There are special ceremonies held by the coast by decorated boats
• December 24th, Christmas eve: Kids go door- to-door and sing christmas carols (κάλαντα, /kalanda/) accompanied with triangles and drums. It's a cacophony, but it's cute. They usually expect money or sweets in return (money is more appreciated) or even both, so make sure you're stocked with coins! Some religious households bake "christopsomo" (χριστόψωμο, meaning Christ bread), a ceremonial round loaf of bread with religious markings on top. There's a midnight mass for the religious ones too.
• December 25th: still no gift giving, this day focuses on feasting and gathering up, usually famillialy. Tables overflow with festive cooking, including christopsomo, melomakarona (μελομακάρονα, a syrupy biscuit) and kourampiedes (κουραμπιέδες, a spicy, dry, crumbly biscuit with a generous sprinkle of icing sugar, enough to make it look snowy). Some of the most religious have been fasting for quite some time till this day comes as well.
• January 1st, new year's, st. Basil's day: Now's the time for gifts! St. Basil (Άγιος Βασίλης, Ayios Vasilis) is our own version of Santa Claus, so the children get gifts on new year's instead of Christmas. Another feast happens, and usually ends gloriously with the Vasillopita (Βασιλόπιτα) which is something like a dry cake with a single coin inside. It's split radially in pieces or in squares, each one given to a single member of the table, except for some that are "given" to Christ, to the holy Mary, to st. Basil, to the house, etc. so you always cut more pieces than you actually need. Someone's piece will have the coin inside, they "win" the year and are said to have good luck. Companies also tend to hold Vasillopita ceremonies later in the year, and in those ones whoever wins the coin gets generous gifts, like a bonus or extra time off.
• January 6th, Epiphany (Θεοφάνεια, Theofaneia): The Christmas season concludes with Epiphany celebrations, where brave souls dive into cold waters to retrieve crosses blessed by priests, commemorating Christ's baptism and marking the end of the festive period.

Canada. We're heathens. We celebrate solstice.

The others are starting now. Some go for months with the decoration and tree. It's stupid.

Another UK perspective here. When the decorations go up may depend on the weather and/or the mood of anyone in the house. Each household will have their own preferences and rules for that and everything else.

Putting the decorations up in November is considered a bit soon, but I have some family precedent regarding that, and there was also something on the radio a few days ago about how particularly dreary weather has convinced a few people to get the Christmas tree and lights out early to brighten up the place.

Some put them up at the start of December, but the sensible time is usually a couple of weekends before the big day.

The superstition about taking them down again before Twelfth Night runs fairly strong here, but mostly because it's "right" to take them down at that time rather than any courting of misfortune. (Or is it?)

As for other traditions, that's harder to pin down. You don't know that what you're doing might be unusual until you see other people's perspectives. Everyone knows what a ~~horse~~ reindeer is... Right?

Guarantees: Kids up at the crack of dawn ripping wrapping paper off presents. Someone will want to watch the King's speech and someone else won't. Someone will put on music that someone else doesn't want to listen to.

For the adults around me (and me), we generally wait until after a late breakfast on the day itself to exchange gifts. Then there might be some visiting out or receiving visitors. Visitors might stay for dinner which is mid-afternoon.

Then it's kids playing with gifts, adults reading any books they might have been bought, and finding something to watch on TV (or streaming or DVD etc.) that everyone can agree on.

... and hoping beyond hope that nothing happens that isn't going to make you dread Christmas next year.

From the US but in Japan. Christmas is a normal working day. Couples often go out for a date night. KFC's chicken (or another fried or roasted one) is a common staple for dinner.

Family will get each other presents. I've heard it's more like one present, but I don't really know. I should ask the in-laws this winter when we go for New Years (the big family gathering time in Japan and NOT so much a big party time with lots of businesses closed).

Australian here. Christmas decorations will go up shortly for a lot of people. They come down a day or two after Christmas.

Obviously the main difference is that it'll be the middle of summer so it'll be unpleasantly hot. A lot of people do BBQs for a shared meal, seafood is a very common thing here for Christmas, especially prawns. Oh and Cherries. Everyone loves cherries for Christmas for some reason. And Pavlova

Other than that, it's probably pretty similar to Christmas in the U.S.

Colombian here. Some people start in November, some in December, some never take theirs out after December. Goverment decorations usually are December.

However, over the years the ammount of people doing external decorations has decreased inmesenly, from maybe 75% to 25%.

Dane here. Decorations go up in December - except for all the people putting up already now (especially lights on houses).

Kids watch "julekalender" (24 episode Christmas drama series where Christmas is always in jeopardy but gets saved last minute - one episode each day).

We celebrate Christmas on the evening of Dec 24 (can't wait until 25th). Usually dinner is pork (with the hide roasted such that it is crispy) or duck with potatoes and sauce. Potatoes ar sometimes caramalized, like candy apple. Dessert is risalamande, a rice pudding with whipped cream and chunks of almonds. The person that finds the sole uncut almond wins a prize. We then turn on the lights of the Christmas tree... And dances around it singing (this is where foreigners really starting giving confused stares 😂). When done we open our gifts and have a hyggelig time.

For Norway it depends, really...

We get the small things (lights, figurines) out with advent starting, so late november/early december, but don't do the tree until the night before (23rd). The outside lighting we usually do a bit earlier, as it gets super dark here and it looks nice.
Some people do it much earlier.

Special traditions for Norway would probably be porridge with an almond in it. The one who gets the almond wins the marzipan prize.
Our family does it a bit differently: There are many almonds, the total changing every year and only Mum knows, and the one with the most gets to pick from the prize pool first. That way, everybody gets something and the kids are happy.
I finally won last year with 14.
It's also super fun watching people looking like chipmunks, hiding their almonds until it's time to count.

Pretty much the same, except that the main celebration (and gift-giving!) occurs on the Eve, and the songs are depressing.

It's just December

Pretty much a regular family hang out but with more food and some token decorations (one year we had a single christmas bauble on a small orange tree).

Spain. Right after Halloween (years ago was even before) and they stay until someone remembers to take them off. Sometimes April.