Every year around September or October, Shanghai enters mooncake season. Supermarkets fill up with gift boxes, offices start collecting pastries, and everyone develops an opinion on one important question: are fresh meat mooncakes actually good, or are they just a Shanghai thing?
What are the origins?
So. In Chinese mythology, there once was an archer named Houyi, who was kind of a big deal. Legend has it that he was given an immortality drug by Xiwangmu, the Queen Mother of the West, as a reward for taking care of a little global warming problem they were having at the time.
For some mystical reason, he didn't take it immediately. Instead, he left it with his beloved wife Chang'e while he went out hunting.
From here, the story splits. If you're a Disney fan, take this version: the drug was only good for one dose and Houyi didn't want to take it alone. Then word got out, someone tried to steal it, and Chang'e ended up taking it herself to keep it out of the wrong hands. We're speeding through some things here.
The drug kicks in and Chang'e starts floooooaaaating up to the sky. She becomes an immortal goddess and settles on the moon. Houyi, devastated, starts making offerings to her under the full moon. Other people join in. And thus: the Moon Festival. Romance, immortality, and a fairly extreme long-distance relationship.
There is also a darker version, in which Chang'e simply steals the drug from her trusting husband and leaves him for good. She still ends up on the moon, where she has to hang out with a rabbit for the rest of her life. Maybe stick with the first version.

So is it just about eating mooncakes?
Not exactly. Although the mooncakes are hard to miss.
Mid-Autumn Festival is one of China's major traditional holidays, held on the 15th day of the eighth lunar month, usually sometime in September or October. The full moon symbolizes reunion and togetherness (tuan yuan, 团圆), which is the general theme of the holiday.
In practical terms: dinner, mooncakes, and, weather permitting, looking at the moon.

Why are mooncakes everywhere?
Because they're the festival's signature food, and also a very convenient thing to put in a box and give to someone.
Mooncakes (月饼, yuebing) come with all kinds of sweet and savory fillings. In Shanghai, the seasonal favorite is the fresh meat mooncake (鲜肉月饼): flaky pastry, hot pork filling, best eaten fresh, and frequently accompanied by a queue outside the bakery.
Every year, people debate which shop makes the best ones. There is rarely a final answer.

What do people actually do during Mid-Autumn Festival?
Have dinner, exchange mooncakes, admire the moon if anyone remembers, and enjoy the time off.
It's generally a much quieter affair than Spring Festival. Some people travel, some head home, some take a short autumn trip. Mostly, it's a few days to eat well and not be at work.

Why does my company keep giving everyone mooncakes?
Because mooncakes are one of China's great seasonal gifts. Companies give them to employees; businesses give them to clients and partners; people give them to relatives and friends.
This has created an entire secondary industry devoted to putting mooncakes into increasingly elaborate boxes. Some look considerably more expensive than whatever is inside them.

Is Mid-Autumn Festival a big deal in Shanghai?
Yes, but it's not a particularly loud holiday. You'll notice it mostly through the mooncake queues, gift boxes piling up in offices, family dinners, and the fact that everyone is suddenly discussing the lunar calendar.
It's also one of those Shanghai things that sneaks up on you. The first year, you're wondering why everyone keeps giving you mysterious boxes of pastries. A few years later, you have strong opinions about which fresh meat mooncakes are worth queuing for.
That's probably when you know you've settled in.

So when is the Mid-Autumn Festival holiday in 2026?
In 2026, Mid-Autumn Festival falls on Friday, September 25, giving people a three-day holiday from September 25 to 27.
The good news: after that, there are only three working days before the National Day holiday starts. The less good news is the usual Chinese holiday calendar Tetris: Sunday, September 20, and Saturday, October 10, are working days.
Check your calendar before making plans.