checking timing on 91 civic dx?

ok I got a inductive advance timing light from my friend but am not sure how it exactly works, I have found the wires under the dash on the passengers side that I need to hot wire and have found the 3 marks and the white mark on the crankshaft but how do I exactly check the timing, this is what I did, I set the dial on the gun to zero, connected the wire clip on the gun to the first cylinder and flashed the gun on the crankshaft, now should the timing pointer on the cover be aligned with one of the 3marks or the white mark? my timing should be at 16-20 BTDC how do I know whats my timing exactly? cause as of now it doesnt align with any of them lol...or should I turn the dial on the gun to 16!! any help appreciated thanks

to check where the timing is at right now, shoot and adjsut the knob until the lone white line is lined up with the mark. look at the knob, that is where the timing is at right now. if its at 16 degrees(+ or - 2 degrees, it is fine).

with the advanvce timing light, dial the knob to 16 and shoot. adjust the dizzy so it lines up with the lone white line and the timing marker with the knob still set at 16 degrees. tighten dizzy and reshoot to make sure it has stayed at 16 (+ or - 2 degrees)

if you are using a inductive timing light with no knobs.............................just shoot the timing and adjust the dizzy so the red middle mark of the 3 marks line up with the timing marker. tighten, reshoot to check, and you are done.

thanks for the reply, I will be taking it to be smoged in a couple of days, you think its better to have the timing closer to 16 BTDC or to 20 BTDC. the specs says (16-20) so which end is better as far as running cleaner? thanks