YY DDD = year year day day day where:
"YY" = two digits representing the year in which the product was manufactured, and
"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 (i.e. the "Julian date").
Utah Admin. Code R307-357-10