A body was discovered on the 23rd floor of the Hilton hotel located somewhere between the Pacific and the Atlantic oceans. Ambient room temperature set at a reasonably comfortable 20⁰C, the body chills according to Newton's Law of Cooling. A living and breathing person's body temperature is 37⁰C. It is also known that in similar conditions body temperature drops to 35⁰C after only two hours. If the corpse was found at 4 pm at a temperature of 30⁰C, when did the murder take place? Explain your reasoning.