If you go the microcontroller (uC) route you will need at least a display of some sort, keypad, uC, crystal, battery holder, enclosure and ancillary components (resistors, capacitors) depending on the chosen uC. Do you have uC programming skills and equipment? The circuit diagram would clearly depend on the choice of uC and display.
Another option might be to use a digital alarm clock to trigger a 2hr timer made using a 555 chip and driving the LED (if the 2hr period isn't critical).