双11购物

11/11, Singles' Day (光棍节), was reframed in 2009 by Alibaba founder 马云 (Jack Ma) into a single-day e-commerce festival on Tmall. By 2021 it cleared ¥540 billion in 24 hours and became the world's largest shopping event, dwarfing Black Friday. 双11购物 is the umbrella activity: pre-sale deposits, midnight flash buys, livestream coupon hunts.

双11 (or 双十一) is read 'Shuāng shíyī'. Add 购物 and you have the activity ('Double Eleven shopping') rather than the date. The whole sale now stretches across two waves and runs about 3 weeks despite being branded a 'day'.