I don’t think the dal fry would be spoiled if left out all day because in my experience I haven’t seen it yet. However, there are some conditions that you must comply with. Such as:
Do not refrigerate the Lentils in hot conditions.
The prepared dal fry should not touch by hands, as it can be spoiled by germs from sticking to the hands.
Also, you can use Ajinomoto (MSG) when creating the recipe, it will help keep your recipe fresh for more than a day.