Answer #1: Hi, If it has just been
cooked then it will keep for up to a week in a normal fridge. Keep it well
covered or sealed in. -- Ed Martinez Comment
Answer #2: The UK government health authority website has a page on how to store food safely and recommends keeping leftovers in the refrigerator for no more than two days. They also say it should be put away within 90 minutes. -- Rouhi Comment
Answer #3: Absolute maximum a week, but five days to be on the safe side. If you have some food in the fridge and it has been there a few days and you want it to stay good for a few days more you can heat it fully, cover immediately, and when it is cool put it back in the fridge. If you have lots of leftovers why not consider freezing them, food costs are rising so it makes sense to be smart with food and most food items, when frozen can keep their taste in the freezer for a couple of months. -- A Brennwald Comment