The calendar emoji used to mark World Emoji Day shows July 17.
World Emoji Day is observed every year on July 17, a date chosen by Emojipedia founder Jeremy Burge in 2014. The choice reflects Apple's calendar emoji, which displayed July 17 in early versions of Apple's emoji artwork because iCal was announced on that date in 2002.
The celebration is not an official United Nations holiday or a Unicode Consortium standard. It is an informal global event involving emoji announcements, themed events, social-media posts and the annual World Emoji Awards. Different platforms may draw the calendar emoji differently, but Apple's familiar design helped make July 17 widely recognizable.
A common mix-up is assuming the date was selected because emoji were invented on July 17. Emoji developed earlier in Japan, while the date became associated with the modern international celebration later.