The way to know for certain which year your bicycle was produced is to use the archive information available on our website. Our online photo and information archive dates back to 2002 (if your bike is older than that, refer to the instructions at the bottom). Each model will have a different parts specification and paint job from year to year. You should be able to visually verify the year your bicycle was produced by comparing it with the archived photos and simply use the process of elimination to find your bike.
The online archive can be accessed by going to Specialized.com, then hovering your cursor over the "support" button on the upper right-hand of the page. Then, in the drop-down menu which appears, click "bike archive."
If your bicycle is older than a 2002 model, you can use other online resources such as Bikepedia to find more information.