Timing light with dial knob....couple ?'s
 

Ok I got me a timing light with the dial knob on it....You know where can can set the light from 0 to 40 degrees.

A guy was telling me to set the knob to to the desired setting (in my case I am shooting for 15 degrees.) And then I hit the "0" mark on the harmonic balancer and that is 15 degrees.

Is this correct.

yes.

Yes thats it.