Decision Day is a holiday celebrated by the people of The Island.
History and Customs
While The Island is normally impossible to escape, once a year the tides turn and the coastal shelf floods enough that anyone can sail away.
After Ishmael took over as Facilitator, Decision Day became a holiday. All year long, the colonists would build an outrigger, which would be completed for the day. When the tides turn, the island would have a feast and talent show, and then anyone who wishes to leave would take a bite of bitter apple- the horseradish-apple hybrid from the far side of the island- and spit it onto the ground, before boarding the outrigger and bidding the colonists farewell. In the event that nobody leaves, the outrigger would be set on fire and sent into the sea.
The only known people to have chosen to leave are two unnamed women who left with the Incredibly Deadly Viper, and Thursday, who left while his wife, Miranda Caliban, was still pregnant with their daughter, Friday. Nobody had left after Friday's birth.
The holiday was destroyed the year the Baudelaires arrived on the island, as several colonists revolted, and Ishmael and Count Olaf released the Medusoid Mycelium, poisoning the islanders and causing them to flee on the outrigger, destroying the colony.
- Decision Day could fall on January 28. The Calendar states that Kit Snicket was reported "either missing or on vacation" January 27; as the Queequeg was a VFD submarine, they likely would have some notification if it was destroyed, meaning she would quickly be reported missing. If she washed up on The Island the morning after/of the storm, she would have given birth the next day, making her death, Beatrice's birth, and Decision Day happen on January 28. However, the calendar's canonicity has been controversial, and it is also unknown exactly when she was reported missing, so this is not certain.