A computer’s build date is the date that the computer was manufactured. This information is important when buying or selling a computer. Build date information can also be necessary for various technical upgrades. Build date should not be confused with the shipping date, because a computer may have been in stock for months after being manufactured. Every MacBook computer contains build date information that users can access.
Open the "Apple" menu and select “About This Mac.” Click on the “More Info…” button.
Locate the serial number for your Macbook in the "Hardware Overview" window that opens. The serial will be 11 characters long and contain a mix of letters and numerals.
Use the serial number to determine the build date. The first two characters are a code that indicates the factory where the computer was made. The third character is the build date year. It is only a single digit. The number five, for example, would indicate a build date year of 2005 unless the computer is obviously very old, in which case it would indicate 1995. The fourth and fifth characters in the serial number indicate the build date week of the computer. The number 49 would indicate that the computer was manufactured in the second week of December.