Converting a Julian Day into Month-Day

[#1]

I receive material from a supplier that uses an encoded date in their material lot, which I'd like to convert to a regular date. It first encodes the three digit Julian date into a two-digit Base 36 hex, which I have found JMP can easily handle.

But converting the Julian date to month-day has been surprisingly elusive. There isn't a mention of Julian conversion I can find. Seems like I should be able to divide the JMP time by the number of seconds in a day or something.

I suspect someone here will know an easy solution.

Thank you.

Attaching the Julian look up table I was given.

[#2 · Accepted solution]

Check out the In Days() function. It will take your Julian date as an argument and return the number of seconds in that number of days. 

You can add that result (minus 1) to January 1 of the year in question.

jdate=239;

year=1998;

date= datemdy(01, 01, year)+(in days(jdate)-1);

format(date, "mm/dd/yyyy");

You might find Using dates, times, datetimes and durations in JMP helpful.