From government food safety site:
"Uncooked rice can contain spores of Bacillus cereus, bacteria that can cause food poisoning. When the rice is cooked, the spores can survive. Then, if the rice is left standing at room temperature, the spores will germinate into bacteria. These bacteria will multiply and may produce toxins (poisons) that cause vomiting or diarrhoea. Reheating the rice won't get rid of these toxins.
So, the longer cooked rice is left at room temperature, the more likely it is that bacteria, or the toxins they produce, could stop the rice being safe to eat."
Don't eat that shit, it only takes 20 mins to make new stuff on the stove.