During nine years of blackguarding the J. D. Edwards date format (also known as JDate, also misnamed Julian Date), I have resisted learning to write DB/2 stored procedures because the need to use them while developing OneWorld applications is minimal and OneWorld is the only context in which I have encountered DB/2. Well, I have finally encountered that special confluence of necessity and available time that produces a tool — in this case a function. I broke down, I learned, and I wrote that JDate to DB/2 Date function. Here is that code, in case you should find it useful:
-- We have to set the delimiter to ! so we can use -- ; inside our function. This is an intelligent comment -- just for DB/2, but don't forget to tell your SQL tool to use !. --#SET DELIMITER ! drop function myuser.JToDate! CREATE function myuser.JToDate (JDEDate decimal(8,0)) returns date language sql deterministic no external action begin atomic if JDEDate = 0 then return null; else return date(char(1900000 + Round(JDEDate, -3) + (JDEDate - Round(JDEDate, -3)))); end if; end! select JToDate(108098), JToDate(0), JToDate(imupmj) from F4101!
I recommend the DB/2 SQL Cookbook as a pleasant mix of examples and syntax flows from which to learn.