Kinda of remember this topic before, I think it was in the old forum. If I right the last digits after reading the DOT #'s are the date. The first two digits are the week, and the last two were the year that they were mfg. My tires on my 30sk were mfg 3307. That would be the 33rd week of 2007. My 5'er came of the assembly line the 3rd week of Oct, 2007.