Arnold's Year 2000 Checklist

A Guide for Individuals and Small Businesses

by Arnold Reinhold

[Not much happened at midnight December 31, 1999. Even the parties weren't all that great. A lot of hard work went into making sure there would be few problems. Thinking about how to prepare for wholesale failure of information infrastructure was a good thing. We've just about use up our Y2K toilet paper and Cheerios. We've left the rest of this paper unchanged as an historical document and as preperation for the next monster date issue, which will be January 19, 2038 when Unix clocks roll over. See for lesser problem dates. -- agr 2001-8-29]

The hoopla about the Year 2000 problem will continue to grow as the feared date gets closer and closer. This problem, also known as the Millennium Bug or just Y2K, results from the computer programmers' storing the year as a two digit value, a practice that dates back to the time of punched card systems. Many computer programs will exhibit faults when the Year 2000 arrives.

We think the most alarmist predictions will not come true. Here's why:

However no one can say for sure what will happen on January 1, 2000! Problems may occur in almost any sector of our economy. The more resilient you can make your household and your organization, the more ready you will be for anything that may happen.

There is a lot of Year 2000 advice out there, but most is oriented to telling large organizations how to set up their Year 2000 committees, with statements like "Task the agency's quality assurance staff to review the business continuity planning processes." Here is a personal checklist of actions you can take to get ready for the big day. If you think these recomendations are extreme, you should see what the pessimists are saying!

For the most part, preparing for the Year 2000 involves common sense steps. You should treat the Year 2000 as you would a major weather situation, such as a hurricane or blizzard warning. Prepare to survive for a few weeks in case essential services are interrupted. Fortunately, you do not have to tape your Windows.

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What kind of problems can you expect with your computers?

The problems you can expect depend on the type of computer your are using, its age, whether it is networked and, most importantly the application programs that you rely on.

Generally the older the computer and application program, the more likely it will have Year 2000 problems. Also, specialized application programs are more likely to have problems than those developed for mass markets. Year 2000 problems are also more likely to impact computers that are networked together. Here is a quick rundown:


According to Apple, all Macintosh computers and operating systems will work properly in the Year 2000. See You should still test any application programs you rely on.

IBM-PCs and compatibles

Besides the issue of application programs, the biggest cause of Year 2000 problems on PCs is the real time clock chip on your computer's mother board and the built in software, called BIOS, that handles that clock. There are two common problems, called roll-over and date retention. The roll over problem only applies to New Year's Eve 2000. Many PCs will not automatically switch from 1999 to 2000. There are software patches to fix this available on the Internet, or you can just plan on resetting the date when you first turn your computer on in January 2000.

The second problem, date retention, is far less common, but more serious. Computers with this problem can be set to a year 2000 date but will not remember the date properly when turned off and back on. Generally a mother board fix or replacement is required to fix this problem. Other solutions include setting the date to 1984 (see Back to the Future, below), or just remembering to set the date each time you turn the computer on.

Other parts of Winsows 3.1 and 95 may have problems. There are fixes for most of these at Microsoft's Year 2000 web site,

Unix systems

Unix software generally handles date conversion properly, at least through 2037. Some Unix systems may have problems and require patches. Check with your manufacturer. For older Unix systems that cannot be fixed, consider setting the system date to 1972 (see Back to the Future, below).

Embedded Systems

Microcomputers are in everything these days: microwave ovens, VCRs, automobiles, medical instruments, railroad locomotives, factory machinery, power plants, etc. Many of these computers are not aware of dates at all, but some are. The possibility that some of these embedded systems will fail on January 1, 2000 is the source of much of the alarm surrounding the Y2K issue.

Check with the manufacture of any critical embedded systems that you own. This is especially important for medical instruments and other life support devices. Develop manual backup plans where possible.


If you are part of a network of computers that exchange data, you have the added burden of worrying about what the other companies are doing. Even if everyone makes their systems Year 2000 compliant, they may use differing approaches, making interchanging data difficult.

Legacy systems

Systems originally based on older mainframe or minicomputers generally have multiple problems with the Year 2000. There are many sites on the Internet devoted to these issues. Unfortunately, many just outline processes for assessing, prioritizing, repairing and testing that are far too complex to be done in the time remaining. If you can, replace legacy programs with Year-2000-compliant commercial off-the-shelf solutions. If you haven't started repairs yet, you may not have any other choice.

Testing your computer

Caution: Back up your computer before doing this test!

Date retention test

Set the date for January 1, 2000 and turn it off. Wait a few minutes and make sure your computer boots up properly and the date is still January 1, 2000.

Application test

While the year is set to 2000, try out each programs you rely on to see if it is working properly. At the very least, create, save and re-open a file in each application. Also set the date to February 29, 2000 and see if your computer accepts this date. Don't forget to set the date back to the current date when you are done.

Roll-over test

Set the date to December 31, 1999 and the time to a few minutes before midnight (e.g. 23:58). Turn the computer off and wait a few minutes. Then turn it back on see if the date has changed properly.

Many PCs fail this test and reset themselves to January 4, 1980,when they reboot. If your computer does not need to be running on New Year's Eve, just plan on resetting the date when you first turn it on in 2000. There are also software programs you can install to fix the roll over problem. See, for example,

If your computer does fail the Year 2000 date retention or application tests, check on the availability of firmware, operating system and program upgrades. Most vendor Internet sites have a Year 2000 section.

If need be, plan to buy a new computer by the summer of 1999. Don't wait until the last moment. New computers may get pricey in late 1999 and getting help if you run into a problem upgrading software will be just about impossible.

Back to the future

If you want to continue to use an older computer that chokes completely on the Year 2000, consider setting its clock to an earlier year. Note that there are just three leap years in the 20th century that start on Saturday, as does the Year 2000. Those years are 1916, 1944 and 1972. If you set your computer's clock to one of those years, the day of the week will match the day of the month on your computer and will continue to do so for decades to come (until the computer thinks the year 2000 has arrived or until the real year 2099 comes).

Unfortunately, IBM-compatible PCs cannot be set to dates before 1980. If you cannot get your PC to work properly in 2000, one possibility is setting the year on those computers to 1984 when 2000 starts. The year 1984 is a leap year, just like 2000, and 1984/1/1 is a Sunday, while 2000/1/1 is a Saturday, so the computer's day of the week will always be one day ahead of reality.

Note: If you make this kind of year adjustment in 1999, remember to set the computer a year earlier. For example, if you plan to use 1972 in lieu of 2000, then , say, on December 17, 1999 you set your computer to December 17, 1971.

What you can do

Here is a checklist of Year 2000 precautions that you should take:

As soon as possible

For small and not-so-small businesses

Here is a checklist for businesses:

Here are month by month suggestions:

January, 1999

March - May 1999

June, July, August 1999

September 1999

October 1999

November 1999

December 1999

Last days of December 1999 (or before you go on vacation)

Friday, December 31, 1999

Saturday, January 1, 2000

Sunday, January 2, 2000

Monday, January 3, 2000

January 2000

Monday, February 28, 2000

Throughout 2000



Our Year 2000 advice can be summarized in a simple slogan:

Back-up, Stock-up, Cash-up, and Check-up

Warning: The Year 2000 problem is very complex and no one knows all its ramifications. This checklist is not and cannot be complete. Get additional advice. You must follow your own best judgement as to what to do or not do.
Copyright © 1998 Arnold G. Reinhold, Cambridge, MA "All Rights Reserved"

1998-8-2, rev 1999-1-16, 23, 11-26