The LA Fox Developer Newsletter

March 1996

FOXPRO 2000 and Beyond

by Gunter C. Mayer CompuServeID: 74163,2215

A patch for the PC Systems Date and a Function to control the

limits of Foxpro Date Handling after Y-1 999.

By now most FP Developers must have heard or read tidbits of

grave Millennium Warnings concerning Y-2000 Date Handling,

all super alarming, but ALL without specific answers. Having

authored two very Date sensitive Applications, which are in

intense daily use, I naturally started to wonder how this would

affect my life on New Years Day 2000. Like do I have to stick

around??

So I decided to spend some time on this subject and came up

with some very interesting discoveries AND a clean solution, in

the form of a Date Function MCDATEO, which I want to share.

1.0 DEFINING THE PROBLEMS

FP Applications written in 2.5, 2.6 and Visual Foxpro all share

the same Date Processing Fundamentals embedded in its

Functions and Defaults. Here are the main areas of concern:

1.

The PC Sys Clock Y-2000 Date quirks migrating to

the FP Date() Function.

2.

The FP embedded, non-programmable Century

Default of 1900- 1999.

3.

“Set Century” dominance over the size of Dateboxes,

ignoring Picture Clauses.

4.

Performance and Century Range of FP Date Func-

tions.

5.

Handling of current Transaction Dates (Systems

Date), versus “historical” Dates, which would fall outside the FP

Default Century.

1.1

Pc Systems Date

It has been alarmingly reported, that the PC World, as we know

it, will come to an end at midnight Dec. 31, 1999, with 99% of

present day PC’s going nuts, especially when the power is off.

The problem lies with the CMOS Clock Chip and in the DOS!

Windows OP Systems, which sound-ed fatal to me, until I found

YEAR2000.ZIP on the Web.

It contains YEAR2000.TXT and YEAR2000. EXE, which patches

the transition flaw. I installed and tested it and it works. Thanks

to GT Becker, Dallas TX.

1.2

Set Century [ON/OFF]:

My conclusion: Set Century introduces complications that can

be avoided. The most important feature here is that this switch

primarily affects the Format of recording of Date Entries, the

Date Entry Format and the attachment of the Century Indicator

to the Date, whether the actual or the FP Default Century

Indicator is attached. Did you know that this setting also over

rides your Picture Clauses of Date Boxes?

OFF: Records the Date in [MM/DDIYY] Format. FP adds its

embedded Default Century Indicator of 1900- 1999 as if there

was no tomorrow , and it also ignores any Century Indicator

added to the Date Entry. When later set to ON, all Years

default to the 20th Century Indicator, thusthe Year [/21] will

become 1921.

ON: Records the Date in [MM/DD/CCYY] Format. When later

set to OFF, the display Format becomes [MM/DD/YY], but the

actual, not the default Century Indicator, is used in Date Calcu-

lations.

1.3 Picture Clauses:

Here is the first Grande Surpriso for me!

They are totally ignored when displaying an © GET {DATE}

Field. FP crudely pops its default Date Box Size onto your form.

OFF furnishes an 8 digit, ON a 10 digit Date Box, adding that

almighty 2 digit Century Indicator without regard to Real Estate

crowding or overlap. For example...

Set Century ON.

@GET dDATE Pict ‘99/99/99’

Bingo, the resulting display is ‘MM/DD/CCYY.

Conclusion: Without a Function, some major rework might be

required here! This has a definite affect on your Screen Real

Estate. For specific [CCYY] Date Entries I may have to [Set

Cent ON] before the @ GET.

1.4 Century Ranges of FP Date Functions

To start with, a refresher of the confusing Century Date Ranges

of Foxpro Date Commands, and later an individual look at

things.

2.0 Review of DP Date Functions

2.1 Foxpro Systems Date [DATEO]:

It takes its values from the internal PC Date Clock. It can NOT

be changed from within FP, but no problem, our little EXE File

has this one handled OK.

2.2 Date Functions (Assuming the 20th Century):

In my opinion, FP has over restricted some of the flexibility that

might be expected by developers. The Default Century Indicator

(100 year Range) should be programmable in the Config.FP

File, for example 1950 to 2049 and it definitely should stay the

heck out of my picture clauses. After testing, I created two

categories for these Puppies:

( Con’t, page 6)

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