None of us can say for sure - all we can do is say what we THINK would happen in that case. But I'm sure lots of people have considered this and will be happy to discuss what they think they would do.

Perhaps people would spend all their lives trying to find a way to cheat the fate and to live longer. Or shorter, which would also be a challenge. I wonder what would happen to those who jumped off a skyscraper. Would some invisible force catch them in the air and carry safely to the ground? That would be fun. You could do anything and live absolutely recklessly. Food would mysteriously emerge in your fridge so you wouldn't die of starvation before your death date. You could walk naked in deadly frost or through fire. You could even walk on the moon without a space suit.