Is there a way to decode the serial-number of your Mac to get more information ?
Few ways found after searching -
1. Mac Tracker
Mactracker provides detailed information on every Apple Macintosh computer ever made, including items such as processor speed, memory, optical drives, graphic cards, supported OS versions, and expansion options. Also included is information on Apple mice, keyboards, displays, printers, scanners, speakers, cameras, iPod, Apple TV, iPhone, iPad, Wi-Fi products, Newton, iOS, Mac OS, and OS X versions. http://www.mactracker.ca/
2.Coconut Battery 2.8
It has this nice feature which shows the age of your mac inside the App - Calculates the age of your Mac using the coded production date in the serial number of your Mac. http://www.coconut-flavour.com/coconutbattery/
The third digit is the year of manufacture; fourth and fifth are the week. (If your computer has a 12 digit serial, ie the third digit is a letter, then the fourth is the year and fifth/sixth are the week).
I just downloaded Coconut Battery -- it displays information relating to the Macbook's date of manufacture, and, separately, that of the battery. It's a nice tool; of course, I can't attest to the accuracy of the data presented, but I'm assuming it's pulling the information from somewhere credible. (My Mac itself doesn't seem to provide date of manufacture via the Apple System Information panel.)