I am not aware of any Julian date like these. If you know how to interpret them, I am sure I can provide you with how to calculate them in JMP.
If by chance the first digit is the year, and the last 3 digits is the days in the year then
names default to here(1);
code ="L4032 S2";
Year = 2020 + num(substr(code,2,1));
date = datemdy(1,1,year) + Indays(num(substr(code,3,3)));
show(format(date,"m/d/y"));
would show
Format(date, "m/d/y") = "02/02/2024";
Jim