Have you caught any Pokémon on 4th gen before?
Since you're on a cart, you have to save in front of Zapdos, then turn it off and try to hit your delay. When you start the timer and your DS' time, don't insert your cart then, but when you saved your time. Then start your game, and when the first timer runs out, you Soft Reset. Then wait until the second timer runs out, and when it does, press continue. Check if you've hit your delay by calling Elm.
Since you're on a cart, you have to save in front of Zapdos, then turn it off and try to hit your delay. When you start the timer and your DS' time, don't insert your cart then, but when you saved your time. Then start your game, and when the first timer runs out, you Soft Reset. Then wait until the second timer runs out, and when it does, press continue. Check if you've hit your delay by calling Elm.