If you're trying to keep villagers from moving out when you go on hiatus (though the same logic applies to time travelling, since time travelling is like the regular passing of time but sped up), I wrote a guide:
http://www.belltreeforums.com/showthread.php?209379-How-To-Not-Lose-Villagers-When-You-re-Away
Otherwise, don't be afraid of losing your villagers. If you talk to each one of them every day, it's unlikely or even impossible that they'll move out without letting you know. When a villager is planning on moving, they don't plan and move out the next day, so they'll at least try to ping you if they can. If they're not pinging but are thinking about moving, your other villagers will tell you about it if you talk to them enough. You don't even have to play every day as long as you're careful to check whether anyone wants to move and don't take a break that is longer than a day or two without doing something like what I describe in my guide.
If villagers haven't been pinging you and you're worried about it, you can set your clock (I use the 3DS one for this) two or more weeks in advance and start the game as a new character. When Porter gives your new character a map of the station, check the map and see if anyone's missing, then quit the game without saving and set the clock back to the date you had before. If nobody is thinking about moving on your current date, nobody will missing in the future. If someone is, just find that villager and talk to them a few times. If they say nothing about moving, save, quit, load the game again and talk to them a few more times. Keep doing that last thing until that villager pings you and asks you about moving.
Seriously, don't worry so much about it. It's very rare for villagers to move out unexpectedly unless you leave your town for a while and don't take any precautions to keep them from moving before playing normally again. Just think that even if one of them moves, you only have 8 dreamies, so you can get a friend to hold that villager while you cycle. If a game is seriously making you feel nervous and worried, it's not worth it.