AFAIK there is no direct correlation between serial and date of manufacturer per se:
This may help for Nikkors.
http://www.photosynthesis.co.nz/nikon/lenses.html
You can roughly figure it out within maybe a year...
Your best and most accurate bet would be to contact the lens manufacturer with the serial number and they'll should be able to tell you to the day pretty much.
Thank you for the link, that datasheet is excellent, only that it doesn't list the lens I am trying to find out its age (200-400VR).
Its updated by users, so if you send Roland an e-mail he'll add your serial. I've had a lens that was past his end point as well.
It means its a very new lens though.
