All three of these dates are different, which makes it hard to determine the actual build date. The Dev Menu date appears to be a Subversion timestamp, so that could be the date of the actual code; the XEX date would then be when the game was actually compiled. The disc label date is one day after the XEX, so that would be when it was actually burned to disc.
|Sonic games for the following systems|
|2006 Sonic the Hedgehog 2008 Sonic Unleashed 2009 Sonic's Ultimate Genesis Collection 2010 Sonic & Sega All-Stars Racing | Sonic Free Riders 2011 Sonic Generations 2012 Sonic & All-Stars Racing Transformed|