Annoy Squidward Day is a day that was mentioned in the episode "Employee of the Month" as part of a joke.
It is supposedly held annually on the 15th of February. Squidward was bothered, so he asked what day is today and he answered, "is the day to annoy Squidward?" SpongeBob laughs and says that "Annoy Squidward Day" is on this day, and points to the calendar.
- If you look closely on the calendar, below the 15th is the 21st, when it should be the 22nd, so the week appears to only have 6 days. However, this could just be an animation goof. Also, despite that 19-23 are below 13-17, they look as if they're above 24-28, implying an added 5-day week.
- SpongeBob is always unintentionally celebrating this holiday.