i have managed to find a sleeping mod that 'simulates the world while you sleep' here
a mod i would love to see is better AI for mobs. this would make mobs smarter like zombies and skeletons that can break light source blocks and are attracted to light, all zombies able to break down doors and weak blocks like wood and also set wood on fire if carrying a torch, spiders that can climb upside down surfaces like overhangs, have poisonous bites, shoot webs to ensnare their enemy and hang from ceilings using a silk thread, creepers that will attack man made defenses if the player isn't present and skeletons that can steal items from chests. also soldier villagers to protect villages at night and properly fortified villages.
this would make mobs become a proper challenge in minecraft and doesn't guarantee your safety in a fortified base.
also i unfortunately already started a survival world and got well established. (cheats are disabled) so i can't place a command block unfortunately.
Sorry, I don't have a link. Just try to search it on Google.
For survival World cheats you may want to go to the menu --> open in LAN --> enable cheats --> confirm, that will temporarily enable cheats in your world.