I am a total noob, but I feel such cleverness deserves a guess - even if only to prove how far superior your skills. I am unwilling to just shrug and wait for you to reveal your skill without so much as voicing the consideration I have given - not so much a joke, but puzzle - you have provided.

I will guess that there is some capacitance in the circuit and that you use some application of the RCTime constant as a reference; different clocks would, I think, reveal the clock speed by the timer values measured when charging and discharging a capacitor from a known voltage. I take my guess from watching the LED (which, I believe has a capacitance associated - and conveniently a resistor in series) which is slow to start - I'm hoping, because it is busy measuring...