When are spark plugs due for change?
Every 100,000 miles with double platinum or iridium. More often with other plugs. Pull one to see what it looks like.
Your car will ask for it, service "4" is the timing belt service with plugs per Honda/Acura. Car monitors your driving and will ask for it at around 100-120k miles. I must say that they also recommend replacement of the belt every 7 years as the belt will perish over time.