Why? Because that's the date that shows up when you select the calendar emoji?
Is that how "holidays" are made these days? If they can have a National Video Game Day (September 12) and a Stick Out Your Tongue Day (July 19), then why not an emoji day?
But just how does one celebrate World Emoji Day?
Apparently, in Dubai last year they used World Emoji Day to set the Guinness World Record for the most number of people dressed as emojis in one place.