Timing belt

I have a 2005 Honda Civic coupe and my repair advisorat the dealer tells me that I should have my timing belt replaced soonish. Mileage is 53,000. Do I risk leaving it for the summer without replacing it? It will be driven.

To the best of my recollection, Honda changed from a timing belt to a timing chain as of the 2005 model year.
A timing chain is usually a lifetime component, but in any event a timing chain is not changed proactively.
When you begin to hear the chain rattling, then it is time to change it, and this is not likely until after at least 150k miles.

But–you shouldn’t trust my memory on this point.
You need to consult the ultimate authority on this point, namely the folks who designed and built the car.
How do you do this? By opening the glove compartment!

Open your glove compartment, take out the Owner’s Manual, and turn to the section listing the Honda maintenance schedule.
If the car has a timing belt, it will be listed as a maintenance item at 105k miles/8 years (whichever comes first).
If there is no notation in the maintenance schedule for replacement of a timing belt, that serves as confirmation that the engine uses a timing chain, rather than a timing belt.

The maintenance schedule that came with your car is an invaluable resource, and you should really get into the habit of referring to it. Your car will last much longer if you do this.

And, as you have found out the “service advisors” at most dealerships know next to nothing about cars.
Their job–aside from serving as data entry clerks–is to push extra services, about which they frequently have little or no understanding. If you use your maintenance schedule as a reference, you will definitely know more about maintaining your car than this “service advisor” does.

2.0 Litre has a timing chain. The 1.7 litre engine has a timing belt and an interference engine. Your mileage is below the recommended time to change it. Next year when it hits 7 years old might be time to change it based on age.