set_task(float(24*60*60), "function");
public function(){server_print("I'm called 24 hours after set_task()");
}
This will reset the counter every time you change map or restart server since plugins are reloaded then.
If you want something done at a specific time instead of after an amount of time this would be better: https://forums.alliedmods.net/showpo...0&postcount=10