Does a Honda Odyssey van have a timing belt/chain that needs changed periodically as do the Accords? If so, what is the timeframe?

Most cars have a timing belt or chain. With belts, they tend to stretch over time.. anywhere for 60K to 100K miles it should be changed. (It should say in the owners manual.)
Cars with a chain will generally last longer. The Odyssey has a belt. Ask your dealer when it should be done.

Don't put it off too long because if it goes, you can do damage to the valves.

Odyssey has a belt which, according to Gates, should be changed every 90-105,000 miles depending on the year of your van. I highly recommend doing the tensioner at the same time because if that fails, it's the same as if the belt fails. The timing is going to be interrupted and seeing as you have an interference engine, that would put you in a boatload of trouble.

How can I find out if my ford freestar 2004 v6 4.2 l has a timing belt or timing chain

Does my ford freestar 2004 v6 4.2l have a timing belt or timing chain