The Laboratory

Traditionally the penultimate day of the Calendar is a clearout of all the things we wanted to put in but didn't have room for. So here, in no particular order: The classic Henry nativity, born anew for 2025 What kind of monster would put a giant guacamole dip on top of a record player. Everything about this is wrong. And yet ... yum. Woke Christmas decorations. Farage would ban these. Last chance to buy the must-have Christmas gifts for the kitchen. Yes, £600.

It went very well, thank you! We only ticked 6 of these boxes: Anyway, today we are doing tree decorations. These are some of the best we have seen over the last few weeks. That last one for Doctor Who fans. Sorry you're not getting a new episode this Christmas. What are your favourite tree decs? Send us a photo!

Time for some silly presents that you could buy (as if yesterday's toilet roll wasn't silly enough). 1) for the EXCEL fan in your life, from the silly folks at the Financial Times, a vaguely seasonal mousemat. They have a whole range of merch, mainly mocking people who buy crypto. https://www.redbubble.com/i/mouse-pad/Merry-XMATCH-by-FTAlphaville/166878203.G1FH6 2) ornaments seem to be getting sillier and tackier every year. The Covent Garden shop Choosing Keeping has a representative range including these three kitschy classics. https://choosingkeeping.com/collections/christmas2021-breakfastanddeli 3) another nerdy gift, this time from Mathsgear, who have loads of silly toys that actually show some really important maths. Alongside non-transitive dice and , they have these square coasters, each of which is split into different sized squares. If you put all four together, it makes a super-square! https://mathsgear.co.uk/collections/all/products/squared-square-coasters 4) saving...

More tree decorations today, and the range of furry figures that you can get is unprecedented. Here are our favourite three: the Hippy Dog the Suffragette the Arnolfini Marriage The last of those based of course on the well-known Renaissance portrait of Santa and Mrs Claus:

Every so often you come across a Christmas tree ornament that defies belief. This one from Louisa, who says she got it over 20 years ago from a great-aunt who was a nun. Do let us know about any terrible decorations you have but are forced to display because of nuns or whatever.

Welcome to latest (and we hope greatest) online Advent Calendar yet. When we started these the internet was in its infancy, and as well as inventing blogging and Twitter, Adam was getting total random strangers to visit and comment on eclectic Christmas stuff. We even (apparently) got a mention in a newspaper's Saturday magazine (but they weren't online in those days so we only heard about that). Christmas seems to have come very early this year, especially some Carol Services (more on that later). But Advent has come, as it always does, on 1st December. We'd love to hear about your Christmas preparations, what Advent calendar you have bought (or been given), and any requests for daily pics (Hasselhoff in a Santa outfit? Did that in 2005). Just tweet @robotmaths or send us a message below. Today we celebrate Christmas ornaments. Living in a 1930s semi, we were enchanted by this lovely scene from Homesense. Nothing quite says Christmas like a flamingo in a Santa hat in front...

It's arrived! I was forbidden from buying it, until Sarah could collect one from our local newsagents, The Bon Bon of Woking. Mr & Mrs Bon had been saving it ready to hand over with the Saturday Guardian.      1. remove inserts      2. remove the wrap-around front cover      3. grab a Sharpie... The Saturday shop also revealed a super little tree decoration from Sainsburys, only £2. It's a coffee cup with a heart on the top and an actual cardboard sleeve! So because I seem to always be buying coffees for the amazing Music department (especially on Carol Service rehearsal day) I made a little drinks carrier out of card to present their presents! Also in Sainsburys: cursed snowflakes and I do NOT recommend this cheese, especially the cranberry and pepper biggest Christmas cash-in ever

It's time for a Christmas tree round-up. Normally we would post the Tate Gallery tree, but they don't seem to have one this year. In fact, the last one we can find is from 2016, an upside down tree from Shirazeh Houshiary. So instead here are three trees from around Europe. First up is a 20-metre spruce pine donated to the City of Brussels by its owners in Raeren, in the province of Liège, decorated with 600 champagne-coloured baubles and 2 km of LED light garlands. Closer to home, St Pancras always puts on a great display for arriving travellers, sometimes the tree is non-traditional - and this year it's a fantastical collection of hand-drawn London buildings, to raise money for City-Scape. Standing at 33ft tall the design shows familiar silhouettes of the London skyline spread across over 80 terraced houses, department stores, concert venues and more! It took over 60 hours to hand draw all the elements. And finally our new favourite tree, at Waterloo - it's covered in...

More tree decorations today, because quite frankly these ones are stupendous and cool and every tree needs at least one of them. And because Stevie Nicks is the QUEEN and who would have thought of making a bauble of Stevie Nicks, well House of Hackney have ( https://www.houseofhackney.com/uk/ ) and they do great decorations, homeware and COATS so check them out. Plus GRACE JONES.

Some more decorations today. First, Terry's Chocolate Orange holders in the shape of crocheted Christmas puddings. These are made by @snotlady5 on Twitter. On Twitter, David Allen Green has also been asking for great tree decorations. Here's a few scary ones! And thanks to David and Alistair for sharing these before and after pictures!

Happy Election Day! We're big fans of knitted tree decorations (see here , here and here ). But I think even we would baulk at putting either of these two on our tree! For balance, I tried to find knitted Swinson, Lucas, Sturgeon or Price, to no avail. So we'll have to make do with a parliament we can all get behind ... a parliament of owls.

We're always on the lookout for new tree decorations, and with the perennial debate over "Is Die Hard a Christmas film?" you couldn't do better than to make your own "John McClane crawling through a vent": Instructions at:  https://unlikelywords.com/2016/12/23/how-to-make-your-own-die-hard-christmas-tree-ornament/ In other film memorabilia, you could get a HAL 9000 ornament from Stanley Kubrick's 2001, but you might feel it's a bit risky to let a psychotic AI into your home. Still, even that is safer than a chestburster... If you are a fan of the papercraft, though, the best tree dec to make this Christmas is a miniature Commodore 64! Instructions for this one are at  http://rockybergen.com/

You can tell it's the school holidays when the Advent Calendar starts falling behind ... sorry! We have enjoyed meeting lots of friends this December, and a special hello to John B who we caught up with for the first time in 2 years yesterday. While we were round at a party on Saturday we spotted this rather strange Xmas tree decoration. Either Han has got really big or the Millennium Falcon has got very small.

We've spent the weekend getting Christmas stuff ready, though we're not as organised as our friends Jacqui and Linda, both of whom managed to get their trees up yesterday! We have wrapped some presents and a trip to IKEA with Sarah's brother and his wife means that we have a few more decorations to put up. Soon our neigbours will be decorating their house with a Christmas extravaganza of lights, but we prefer this understated one.