I have made a plugin that drops loot whenever players kill mobs. However, in order to prevent abuse, I want the loot to stop dropping if the player has killed more than 10 of that specific mob in the last 12 hours. So if a player kills 10 zombies, they will then have to go kill different mobs in order to keep receiving loot. What would be the best way to do this? I thought about keeping it all inside a HashMap, but the tricky part is that the server has to keep track of the player, every mob the player has killed, and the amount of every mob the player has killed as well, so if a player kills 10 of each mob, that will be a lot of data to store for just that one player. And the trickiest part is that it should only look at the last 12 hours or so. I'm not quite sure how to do this, so I would appreciate any help! Saving it to a .yml file is not necessary. It's fine if server restarts reset the counter.