You can check them yourself. The date is stamped on the side of the tyre. It is expressed as a week number and year. So, 3208, is tyre manufactured in week 32 , 2008.Yes, I thought that as well straight away and asked the tyre depot to check the rears.
They were in better condition than I thought and were only half worn and good condition, so plenty of life left yet. Which was a relief .