The Aporkalpyse Calendar is a naturally occurring structure that can be found behind a Suspicious Crack in the Ancient Pig Ruins on the 5th island. It can be used to avoid or get closer to the Aporkalypse.
The Calendar resembles a clock with a tellurium in the middle, made of three rings moving at varying speeds. All three rings have a sigil on them. To the left and right of the clock are two buttons that reverse and fast forward the clock, respectively.
When all three sigils on the rings align, the Aporkalypse is triggered. This cannot happen while it is nighttime. While the event is active, the rings will not move. The player may step on the buttons to stop the Aporkalypse at will.