The build date is found on the door tag. xx/A=day/January, xx/B=day/February, xx/C=day/March, xx/D=day/April, xx/E=day/May, xx/F=day/June, xx/G=day/July,xx/H=day/August, xx/J=day/September, xx/K=day/October, xx/L=day/November, xx/M=December