in the link he provided it said it can be done using the serial number on the board but that means they use the manufacture date of the board to determine the warranty period starting date.
End User RMA Policy
Please read the following agreement:
GIGABYTE General Policy
GIGABYTE recommends for customers to first contact their vendors for faster replacement or refund transactions. If experiencing difficulties in warranty service through your dealer or place of purchase, GIGABYTE will attempt to resolve this issue.
For faster and more efficient service, GIGABYTE recommends for users to troubleshoot with support technicians prior to requesting for RMA. This may save time and costs for unnecessary shipping of products.
GIGABYTE USA will only provide warranty service to GIGABYTE products purchased within North America.
Warranty Effective On Date of Manufacture
GIGABYTE determines warranty based on the manufacture date. The manufacture date can be verified by the serial number found on the product. The first four digits after "SN" determine the year and week of manufacturing date. For example:
"01)04719331729028(21)SN0213030585" represents the 13th week of 2002