Originally Posted by SkyDog75

You are reading the serial number wrong. According to the FAQ on Giant's web page, the year of manufacture is the third digit of the serial number, but it's really the third character. Thus, your serial number, GU109604, indicates a frame that was built in 2011, which makes perfect sense for a 2012 model.

I don't know if Giant still follows the same convention, but according to BikeForums' resident serial number guru, T-Mar, the second character used to denote the fortnight of the year. U would be the 21st fortnight, which would indicate the 41st or 42nd week of the year -- roughly the middle of October. And again, that makes perfect sense for a 2012 model.