Thanks for that,
No, the Info just reveals the date and time you looked - now!
I realise the modified date doesn't mean much - on a CD I'd expect them to be identical - I just want to find out the file dates so that I can archive stuff properly. Further, if you copy a file from the CD to the desktop it shows the current time and date too. I'm mystified. Interestingly, I've just plugged a CD drive into my partner's MacBook Air and that shows a commercial CD with no dates as well. I'm just astounded. this must mean Finder's never been able to do this, but at least I know. I just seem to find some CDs I can read dates on and others I can't. I just wish I knew why. But Thanks again.