M/C tire age

[Jon Wennerberg <jon@infodestruction.com>]

Hey, someone, please refresh my memory.  While packing for the trip to 
the Salt I found a spare rear tire for my bike.  I'd like to have it 
along in case I need it -- but don't remember how to read the date code 
so I know if I'll be allowed to use it.  What's the secret?  And just 
how old a tire are we allowed to use -- 5 years, or was it six?

                 Jon Wennerberg
Seldom Seen Slim Land Speed Racing
              Marquette, Michigan
              (that's 'way up north)