up to scratch, so that your pet can continue living in the manner to which they have become accustomed.
The other advantage is if you want to keep your pet on a strict eating schedule. Many pets do become overweight from a combination of over eating and lack of exercise. You can certainly place some control over the former by using an automatic pet feeder. The best ones have multiple set up times so that you can set the food to be delivered at very specific times.
You would not normally leave your pet on their own for any amount of time. You might want to feed them in the evening for example, if you knew that you would be home late. All the models that I have come across work for a minimum of 24 hours.