"Date" fields

Date field question...

There may be a few exceptions, but in JDE all date fields are generally defined 
as a 6-digit julian format - 105001, for example, indicates 1-January-2005.  
099001 indicates 1-January-1999.  (The '1' prefix indicates that the date is in 
the 21st century, a '0' prefix indicates 20th century).

Let's say you're defining a date/timestamp field (14,0 Zoned) -or- a date field 
(8,0 Zoned) in a non-JDE data base (DB2).  Is our industry, is there a  
standard for populating these types of field?  I have an idea as to how they 
should be populated, but would like another's opinion.  

Please do not confuse my question with the "date" data type that is now 
available.  I believe that the customer's requirement is to have this field 
defined as a numeric field...

Regards,

Steve