Re: Date validation of different formats in RPG

[James Rich <james@xxxxxxxxxxx>]

On Thu, 1 Apr 2004, Barbara Morris wrote:

> James, your API works on the assumption that the first non-failing guess
> is the correct one.  Depending on what the dates mean, that could be
> dangerous, and in the long run it's less user-friendly than asking the
> user what format the dates are in.

Yes, that is intentional.  We chose that because char2date() is often
called in places where there is no user to ask.  We made a decision that
if a date is ambiguous, assume the *mdy representation.  We could return
FAIL in those cases where there is more than one positive match, I
suppose.  Regardless, in those cases where there is a user sitting at a
screen, we do validate that the date entered is what they really intended.

> I think a date-format guessing routine should check the date against all
> date formats for the date's length, and declare it invalid unless it
> matched exactly one format.

That would probably be more rigorous, but we decided to assume *mdy in
those ambiguous cases.  Perhaps we made the wrong decision.

> 04/04/04 is coming up on Sunday.  (That's 04/04/04 for you *MDY folks.)

That isn't really ambiguous.  No matter what it means 2004-04-04.

James Rich

Zvpebfbsg vf abg gur nafjre.
Zvpebfbsg vf gur dhrfgvba.
AB (be Yvahk) vf gur nafjre.
        -- Gnxra sebz n .fvtangher sebz fbzrbar sebz gur HX, fbhepr haxabja