China's "Singles' Day" is celebrated on November 11, because the date "11/11" often reminds people of "bare sticks (光棍)" in Chinese. Today Singles' Day is popular around China, especially among young people in colleges. In fact, it was invented in a college.
Chinese Singles' Day came from Nanjing University in 1993. Later, several universities in Nanjing celebrated it in the 1990s. The holiday got the name "Singles' Day" because the date is made up of four "1". After graduating, these college students carried the tradition into society (社会). Singles' Day has been largely popularized on the Internet and is now celebrated even by young people in several areas outside China as well.
However, as time goes by, that meaning has changed. Today, Singles' Day is better known as "Double Eleven" because of Alibaba Group Holding founded by Jack Ma. It runs China's largest online marketplace. In 2009, China's online shopping giant Alibaba set the day as a shopping festival because date is easy to remember and it is between National Day and Chinese New Year. It soon became popular, and Double Eleven has become one of the most important days for buyers and sellers across China because everything is on sale on that day.
On November 11th, 2019, it took just 96 seconds for Alibaba Group to sell 10-billion-yuan goods just after midnight.