What festival is 520? I checked the calendar again, but it was different from the yellow calendar. number

2 1 At the beginning of the century, an online festival spontaneously organized by hundreds of millions of netizens-online Valentine's Day, rose quietly in the Internet world. This is the first fixed festival in the virtual network world, which is scheduled for May 20th and May 2nd1day every year, because the homonym of "520" and "52 1" is "I love you".