There is a general perception of how cats act and how they are independent creatures who do not need their owners all that much. This is not generally true and is in fact a very dangerous assumption to be making. While most people know that their dogs are extremely emotionally dependant on them and that unless they are around, their dogs will not be able to stay healthy. This is because dogs are overtly affectionate and show that they need human beings around for stability. While cats are not as attached they are still dependant on their owners and can enter something that can only be described as a state of panic or anxiety when they cannot find their owners.
While cats are generally able to take care of themselves to some extent, you still need to be around them at least once in 24 hours. While you could even stretch it to 48 hours you will still need to make sure your feline friend knows you are around and okay.
The way cats work is that they initially stick to their regular schedules even if they are left alone in the house over night but eventually they will need to meet up with their owners otherwise they start becoming anxious. Anxious feline behaviour is noted by them not going to the bathroom or by not using the litter box when they do go despite being trained for it. If the anxiety grows the cats will stop eating their food or drinking any water and that is very dangerous as the cat can get dehydrated really quickly since it is a small animal. If you plan on being away for more than a day then you might want to get a pet sitter to come in and make sure your cat is doing fine.