May 20 & 21 are China’s Internet Valentine’s Days every year, which are both phonetically the same as “I (5) love (2) you (0/1)” in Chinese.
20 May is more important as a day of opportunity for men to express their romantic love for girls. That means ladies expect to receive gifts or hongbao on this day. This date is also often selected for the wedding ceremony.
As for marketers in China, you should know this festival and utilize the trend to target post-80s and post-90s audience.
Topic #Sweet 520# had seen almost 4 million discussions and over 1 billion views as of 12pm on 20 May 2017.