If the food and water are sufficient, the cat can stay at home for a month. However, the water quality is easy to deteriorate, and two cat litter boxes need to be prepared. If the food deteriorates and the environment is not good, the cat will become sick, so it is not recommended to keep the cat by itself. Leave it at home for a month. Normal cats can stay at home by themselves for about two days, provided that sufficient food is prepared, otherwise the cat is likely to starve to death.