IS Windowing a Problem? : LUSENET : TimeBomb 2000 (Y2000) : One Thread

I read with interest a posting where someone's son had posted a date of 2099 and caused "lock-up" of the system.

My question for you people who are in the know. With increased awareness of Y2K are companies setting themselves up for "problems" from disgruntled individuals who are aware of "windowing" and its limitations?

It just seems with increased "awareness" comes the potential for this problem.

-- Archemedes (, February 14, 1999


One problem that exists for windowing, as I understand it, not being a programmer, is that it converts 2 digit year dates into 4 digit year dates, which is fine as far as it goes, but when the system encounters a 4 digit date from some other system, it has to first change it into a 2 digit date (it has to purposely corrupt it) in order to convert it back to a 4 digit date. Is this correct, you programmers?

If so, it seems like trouble just lookin' for a place to happen.

-- cody varian (, February 14, 1999.

An awful lot of 'compliant' software uses windowing, rather than 4- digit years. In fact, windowing is far more common than expansion in the remediation efforts of almost all large organizations. It's a workable system provided you don't have any data you need to keep for over 100 years, which is true in most cases.

Setting the date to 2099 of course violates the assumptions that windowing is based on, with unpredictable and often nasty results. If you set the date beyond the 'pivot year' used in a particular program or package, you are looking for trouble, and you'll find it.

Determining whether a package uses windowing, and if so determining the pivot year, (and whether it's fixed or floating) has been a major, expensive, time-consuming pain for us. All such testing must be performed using a hard drive you don't mind reformatting a few times a day. Been there.

-- Flint (, February 14, 1999.

The Fortune 50 company that I work for chose the windowing strategy instead of date expansion. With windowing, date fields still have two digits, not four. We (the programmers) have to look at avery line of code in these systems and find every instance where the two- digit date is used in a comparison, or in an arithmetic expression. When we find an instance, we insert routines that test the two-digit date against the "window value" (in this case we use the 1965, which means means the value is "65"). If the two-digit date is greater than 65, we fool the program into thinking that the century is 1900. If the date is less than 65, we fool it into thinking that the century is 2000.

While this technique works fairly well on in-house data ( I say fairly well because it does not work perfectly), everyone has to KNOW that windowing was used and that the actual data is still in two- digit format. If this data is transmitted to another system or otherwise picked up for processing by another system that used date- expansion instead of windowing, that system will be catastrophically corrupted by the two-digit data.

Windowing is a quick-and-dirty fix that will jump up and bite it's creators sooner or later. This whole mess reminds me of the eighties when "junk bonds" brought down the S&L industry. Did those same guys get management positions in the data processing industry?

Date-expansion is the ONLY way to reliably fix a system, and EVERYONE could've/should've made the decision to do this early on.

It's too late now.


-- Michael H. Cumbie (, February 14, 1999.

OK, one more windowing problem. Files are often sorted on a date field, not all that often, but often enough. Using windowing, the 00, or 01, 02, etc. records would end up at the front of a file, not at the back where they belong. I also thing this is a short-cut that will lead so some unexpected and wacky results, IMHO. <:)=

-- Sysman (, February 14, 1999.

Windowing sucks. It's a patch rather than a fix. It will bite those using it in the ass. Different programs (system and apps) can use different pivot dates. This means interface problems. That Fortune 500 company mentioned above is probably typical and why the economy is going to take a big hit, tank, if not TEOTWAWKI.

All of the Microsoft Office crap supports windowing. Any of you think you have "safe" Excel, Access, and Visual Basic Applications ... "be afraid -- be very afraid"

-- vbProg (, February 14, 1999.

I started another thread here at Quick fix for mainframe Y2K bug???
Getting a few good pro comments on date processing if you're interested. <:)=

-- Sysman (, February 14, 1999.

Here's another discussion of windowing, posted today at Gary North's site (please, no comment on Gary's politics). Not my opinion, but to be fair, since it is another programmer... <:)= Windowing Is a Sound Approach, Says Programmer

-- Sysman (, February 15, 1999.


Here's the original, pro- Date-Expansion, anti- Windowing article. It prompted the rebuttal article you posted a link to:

-- Kevin (, February 15, 1999.

Thanks Kevin. I think this is the same link the link has. Darn, now I've got to go check... Thanks anyway. <:)=

-- Sysman (, February 16, 1999.

Yup, same link. Ain't life grand? <:)=

-- Sysman (, February 16, 1999.

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