Admittedly, Christmas treats already hit supermarket shelves back in late summer. But have they started disappearing more quickly? Then that's a sure sign Advent is here. That's particularly true of chocolate Santas because St. Nikolaus Day is celebrated on December 6. On that day, kids in Germany wake up to find their shoe filled with sweets, including an edible version of the holiday's namesake.

In addition to buying excessive amounts of Christmas treats once Advent has arrived, many people also bake them at home. A few of the most popular homemade cookies in Germany are pictured here: spritz cookies, cinnamon stars and almond crescents covered in powdered sugar. Now is a good time to strike up a conversation with your neighbor — you might find yourself on his cookie list.

In general, stores are closed on Sundays in Germany. Rules dictating when shops may open vary slightly from state to state, but most allow for only a handful of exceptions concerning the traditional day of rest. While a rare shopping Sunday may be scheduled at other times of year, most exceptions are planned during the Advent season so no one has an excuse for showing up to Christmas empty-handed.

Festive Advent wreaths — consisting of fresh greenery and four candles — are very common in Germany. While some people decide to make their own, ready-made varieties are also available at every florist. One candle is lit on each Sunday of Advent leading up to Christmas. The first Sunday of Advent falls on December 3 this year.

Germany is world-famous for its Christmas markets and nearly every city and village in the country has one. Many begin selling mulled wine, tasty treats and handicrafts even before the start of Advent. This year, some markets opened as early as November 25. When rows of huts start popping up in German towns, Advent is around the corner.

Mulled wine is certainly a holiday favorite in Germany. It's made from red (or sometimes white) wine, spices like cinnamon and cardamom, sugar and a dash of citrus. While it's a staple at every German Christmas market, it can also be easily made at home. Don't expect to be offered a "Glühwein" in November, but come Advent, it suddenly becomes OK to drink the stuff — at nearly any time of day.

After daylight savings time ends, the days start getting very short. By Advent, it gets completely dark by 5:00 p.m. in Germany. But if you haven't even noticed the darkness because the city is awash in white lights, then Advent is close or already underway. That makes January seem all the more dreary, though...

Advent calendars were first used by Lutherans in 19th-century Germany. Since then, the tradition has spread across the world but remains very popular in Germany. Chocolate is the most common gift behind each of the 24 doors — but you'll also find anything from Legos to sex toys. Has your loved one left you 24 surprises?

These chocolate Advent calendars have been around since the 1950s. You can't really go wrong with these: What kid doesn't like chocolate? Pictured here is an employee in the Wergona chocolate factory in the eastern state of Saxony-Anhalt. Each year, they make more than 30 million calendars, shipping them to 52 countries.

If the bog-standard machine-made calendar sounds a bit too lazy, try making your own. German parents are really into handmade calendars like the one pictured. Some even spend several months collecting little presents to put in each bag or bootee. Mind you, you can buy these calendars and just add the content if crafting's not your strong point.

This calendar from 1910 just showed pictures. In fact, you had to take each picture from a separate sheet, cut it out and put it into the right place. From 1920 onward, calendars had little doors that you could open to reveal a picture. No sweets, granted, but it was a fun way to count down to Christmas, which was and still is the purpose of an Advent calendar.

If you were born in Germany in the past 40 years, chances are you played with Playmobil. It was also the first toy firm to add Advent calendars to its range. Denmark's Lego followed suit in 2004. So, if you don't want your child to eat too much chocolate, it's a good, albeit costlier, alternative.

We all like presents, which is why Advent calendars are not just for children. Yes, this Lego Star Wars calendar is for little ones, but you don't stop liking Star Wars just because you're older, right? Alternatively, you could go for a calendar with beauty products, fancy tea bags or craft beer. You can even get them for cats and dogs.

... are in store, apparently, if you go for this calendar by Orion. Definitely one for the grown-ups.

Forgot to make or buy one? There are plenty of virtual calendars you can register for. Like this one from the Germany Football Association. Each day from December 1 to 24, you can win various match tickets and merchandise.

Thorsten Erny, mayor of Gengenbach in Germany's southwestern state of Baden-Württemberg, calls it the "world's biggest Advent calendar house." It will show a different character from children's books in a different window each day from November 30 to Christmas Eve.