Role in episode
It is supposedly held annually on January 15, however because the animators only added 28 days on the calendar many people also celebrate it on February (It being the only month with that specific number of days), including the offical twitter.
Squidward is bothered, so when he is asked what day it is today, he answers, "Annoy Squidward Day?" SpongeBob laughs and says that "Annoy Squidward Day" is on this day and points to the calendar. It is really the day Mr. Krabs announces the Employee of the Month Award.
- February 15th is also the U.S celebration of Presidents' Day, on years that start on a Friday.