Re: Date Format prior to 1940

[qsrvbas@xxxxxxxxxxxx]

Buck wrote:
> Tom wrote:
> > I would have thought that *CYMD was primarily for support of date 
> > parameters from *CMDs where the CPP was written in RPG. I wouldn't have 
> > expected that it would be used often for persistent storage.
>
> There are several packages that use *CYMD.  Cool:2E (formerly known as 
> Synon) used that format too.  The packages and Synon predate the advent 
> of true date data types.

I don't doubt it. I was thinking more of IBM's driving motivation 
for creating the format in the first place. I can't guess at the 
motivations of developers who used it as an application attribute.

> Date fields aren't perfect, in particular the validity checking is 
> unusual for RPG programmers.

Many years back, I was using QWCCVTDT as my fundamental 
validity-checker for dates. It wasn't always a straightforward API 
to use; but I always figured it's better to have IBM on the hook for 
making it work. If nothing else, it gave a reliable indication of 
validity.

Once a date is known to be "valid" as an actual date, there might be 
other tests such as within a range of dates, after specific 
day-of-month or whatever. But the additional tests are generally 
'business rules' rather than according to common standards.

I'm not sure what to say about developers who can't implement 
'business rules' in the language that they work in.

Tom Liotta