YoWorld Anniversary is an annual holiday celebrated on May 13. Celebrations for it begin on May 8. The event is to commemorate the day that the YoVille was saved from being shut down and rebranded to YoWorld on May 13, 2014 by Big Viking Games. The YoWorld Anniversary falls shortly after the date that the game was first released on May 8, 2008.
The holiday was first celebrated on May 13, 2015. Big Viking Games released the limited time edition theme YoWorld Anniversary 2015 with YoWorld branded items and an in-game version of the Big Viking Games studio in celebration of this holiday.