Led throwie from Hackaday.com. "An LED-throwie which only activates at dawn or night. Add a magnet and you can stick it at metallic surfaces. ATTENTION: For red, yellow and orange use a 120 Ohm resistor. For blue, green or white no resistor is needed." Looks neat, but wish it used some parts that I am more familiar with. Wonder if you could not use just any pnp transistor. And etc...
T 2N4401 = 123AP or 2n3906 or 2N2222?
R GL5516 = generic photo resistor