how long after an event for things to die down

[Reality Jones]

I voted for a year.

One of the biggest killers after an event will be the weather, remember last winter? Now imagine it with no food or heating.

The winter was always the biggest killer in days of antiquity. i think it was the Anglo saxons who used to celebrate a time they called the 'blood month'. It was generaly around the end of October that they would bring all their livestock down from the hills and slaughter what they would need for the coming months, using the pelts for clothes and blankets and smoking and storing the meat for the harsh months ahead.
This would also be the time when they would have to make big desicions about who would survive the Winter. Because the food stocks that had been gathered through the summer months would had to be rationed. The very sick and sometimes the very old would be given nothing and would be starved into the final stages of death.
This festival is still celebrated today, we call it Halloween now and its origins have been almost forgotten. but it still a time when we all stare death in the face.