The manufacturing code is the date the product was made. It might look something like this: 4 122 420 0321.
The first number represents the year it was made. For instance, the 4 in our example code means it was made in 2004. A number 3 would mean it was made in 2003, 2 in 2002, and so on.
The next three numbers represent the day of the year the product was made. In our example, the 122 (or one hundred and twenty second day) is May 2 (May 1 during Leap Year).
The third set of numbers or letters are plant codes, which have nothing to do with the date.
Finally, the last four digits represent the time displayed in military time.