Let the Purge begin! Haha, no, just kidding.
I'd probably gather enough money and supplies (food, medicine, etc, etc-) to be well and such through it and spend it with friends & family [ WARNING : This seller appears to have requested payment via friends & family. This seller may be attempting to scam you via the PayPal friends & family scam which voids all buyer protection. If you pay via friends & family, we will not be able to protect you if the seller does not deliver. ], perhaps doing something exciting and adventurous, after all it'd be the 'last day', so why not spending it with some adrenaline in the system for a few hours and then perhaps travel somewhere with them and look at the beautiful places travelling for some more hours and after that simply relax and wait for the world to be over, eventually.