With Halloween coming up at the end of the month and seeing all those candy for sale one thing that comes to my mind immediately is how the prices for these products drop like a rock the very next day. Essentially, businesses want to get rid of them since they are kind of holiday specific.
This is true for most other holidays as well. Some people even go a little further such as buying Christmas presents for people after the actual holiday as that is when people start returning items and similarly businesses want to get rid of excess inventory.
I guess food items are usually the cheapest in a post occasion day as they have best before dates and of course no one wants to buy expired food which is an even more reason to get rid of it faster before it becomes close to it.