Re: Date conversion technique, alpha to Numeric

Bob Cozzi wrote:

Booth,

I don't see where they referred to a 6-digit date anywhere?
IBM stores dates as the "number of days since..." as a unsigned integer.
You and I don't have access to that integer value, nor do the IBM RPG IV
compiler developers.
We and they only see the external form, whatever form it may be. If it is *MDY,
*ISO, or whatever. All are stored identically in the system.
So a date with an external format of *MDY whose value "02/08/07" is stored as

the same value as an *ISO date whose value is "2007-02-08".

-Bob Cozzi
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-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On
Behalf Of Booth Martin
Sent: Thursday, February 08, 2007 12:12 PM
To: RPG programming on the AS400 / iSeries
Subject: Re: Date conversion technique, alpha to Numeric

This blows my mind. You are telling us that IBM, post-Y2K, is using a mmddyy 6 figure date?

Barbara Morris wrote:

Jerry Adams wrote:

My understanding is that the date is stored on disk in a binary format,
and that it retains the same value regardless of the what DATFMT's value
is.  That is, one program would have DATFMT(*ISO) and another program
could have DATFMT(*USA) against the same table and that it is merely the
presentation, say on a report or display, that differs.

The fact that it is stored on disk in binary format is irrelevant for
program access.

>From a programming point of view, a date variable is always formatted. If you do DSPPFM, you will see the date as the program sees it. With

RPG, because of the way I specs work, you can define your internal
program field with any date format you like (say *ISO), but the
_external_ format in the file will always be the same for that
particular date field(say *MDY).  If your internal format is different
from the external format, RPG will do a conversion for you, but it's not
a conversion from a 4-byte binary to your *ISO program format, it's a
conversion from the file's *MDY format to your *ISO program format.

The conversion from 4-byte binary to the file's *MDY format happens
somewhere deep down in the operating system, where the system prepares
the data buffer.