YY DDD = Year Year Day Day Day
Where,
YY = Two digits representing the year in which the product was manufactured
DDD = Three digits representing the day of the year on which the product was manufactured, with "001" representing the first day of the year, "002" representing the second day of the year, and so forth (that is, the "Julian date").
25 Pa. Code § 130.707
This section cited in 25 Pa. Code § 130.708 (relating to sell-through of products).