Got a Date for the Millennium?
What Genealogists should know about the Year 2000

A version of this article first appeared in the November/December 1998 issue of Ancestry Magazine

By Mark Howells


The spell is broken at midnight

The popular press has finally caught the mis-named "Millennium Bug". Those in the computer industry have been aware for awhile now that some computers will experience difficulty correctly handling the year 2000 as a correct date. This article will review the year 2000 (Y2K) problem and its impact on genealogists who utilize computer technology.

Where did the year Zero go?

First, we'll begin with some clarifications and definitions. While often incorrectly called the "Millennium Bug", the year 2000 problem really has nothing to do with the beginning of the Third Millennium and the start of the 21st Century. Because the year 1 B.C. was followed immediately by the year A.D. 1, the Third Millennium will begin on January 1st, A.D. 2001. It is often incorrectly believed that the new Millennium will begin on January 1st of the year 2000. Since the year Zero was skipped (the West hadn't borrowed the concept of the zero from the Arabs yet when the current annual numbering system was adopted), the First Century A.D. ran from the year A.D. 1 to the end of the year A.D. 100 - a span of 100 years. Likewise, our current 20th Century runs from the year A.D. 1901 to the end of the year A.D. 2000. Our current Millennium thus runs from the year A.D. 1001 to the end of the year A.D. 2000 - a span of a thousand years. The so called "Millennium Bug" will therefore be referred to as the Y2K problem in the remainder of this article.

What's the problem?

The Y2K problem is actually two problems wrapped into one. We'll deal with each separately. The first problem is that some computers and their software store the year portion of any date as a two digit number. For example, the year 1998 will be stored as "98". This can cause failures in arithmetic, date comparison operations, and sorting of dates because systems limited to a two digit year will assume that the maximum value of a year data filed is "99". At midnight on December 31st, 1999, these systems will roll over to the year "00" which can be mistakenly interpreted as the year A.D. 1900 rather than A.D. 2000. A two digit year data field has no method of indicating which "Century" the date belongs to. This may result in illogical negative date calculations (and the creation of many overnight centenarians when birth dates are used by systems to calculate age). Failures in the correct processing of information will result from this date field limitation.

The second problem involved with the year 2000 is due to the vagaries of our Gregorian calendar. In order to synchronize our imperfect calendar with the Earth's actual rotation around the sun, leap years were created. As we all know, every year which is exactly divisible by four is a leap year. There is, however, an exception to this rule and a further exception to the exception. Years which are exactly divisible by 100 are not leap years. So the years A.D. 1800 and A.D. 1900 were not leap years although they were evenly divisible by four. The little known exception to the exception is that years which are exactly divisible by 400 are, in fact, leap years. So while 1900 was not a leap year, the year 2000 will be. Computer designers usually included the "divide by 100" exception when developing their systems to determine leap years. Often forgotten was the "divide by 400" exception so some computer software and hardware will not correctly process the valid date of February 29th, 2000.

What does it mean to genealogists?

There are two implications of the Y2K problem for genealogists - one is general to all of us and one is specific to individual genealogists. The general implication is that the Y2K problem is robbing our computerized institutions of time and effort which could be spent on other projects. Our libraries and archives are forced to cope with the Y2K problem between now and midnight, December 31st, 1999. The computer support staffs which ensure that a library's card catalog function properly, guarantee that telephone systems route calls to the correct information desk, and maintain an archives' payroll system are spending their limited time fixing the Y2K problem in existing systems. Some of these systems are used directly by genealogists and some we never see. However, all must be corrected in order to ensure the continued smooth operation of the institutions which we use in our research. Unfortunately, this means that work on that new computerized indexing system, or the scanning of original source documents, or the creation of a searchable database available on the Internet must be put on hold until the Y2K problem is resolved in the existing systems. There is little we can do about this impact on computerized resources for genealogy other than wait with patient understanding.

The individual implication for genealogists has the potential to have a far greater impact. For our own personal computers and the software upon which we rely for organizing our research, the turn of the calendar to the year 2000 could cause problems.

Our hardware

Most personal computers and separate motherboards introduced by major PC manufacturers (Compaq, Dell, HP, Gateway, IBM, etc.) since the end of 1995 and all Apple Macintoshes handle the year 2000 without any problem. For a list of links to the Y2K compliance information from major PC manufactures, see http://www.mitre.org/research/cots/COMPLIST.html . Older PCs - those built in 1995 or before - may require a BIOS upgrade in order to handle the change to the year 2000.

A computer's basic input/output system (BIOS) usually resides on a read-only memory chip. The BIOS is programmed when it is manufactured to handle computer housekeeping duties such as basic boot up functions and managing persistent data such as the date and the time. It's the BIOS' responsibility for timekeeping within a PC which may cause the PC to have Y2K problems. The BIOS may incorrectly roll the date from December 31st, 1999 to January 1st, 1900 rather than to January 1st, 2000.

There are three ways to avoid the problems of a non-Y2K compliant BIOS. If your PC's manufacturer does not warrant that your machine will handle the year 2000 correctly, you may have the following options. For a BIOS created since 1991, it may be possible to "flash" the BIOS - a process of upgrading the BIOS without physically replacing the chip on which it resides. Some BIOS vendors provide patches to correct the Y2K problem in their product. Finally, manually rolling the date and time past midnight, December 31st, 1999 may allow the BIOS to recognize the correct date rather than relying on its own ability to roll from 11:59 p.m. to 12:00 a.m. on that magical night.

Our software

The genealogical software through which we store and organize our family history represents less of a problem than the older hardware problem described above. First, the GEDCOM standard has always stored dates to show a four digit year. Thus the method by which we share our computerized genealogy will not be effected by the Y2K problem.

The major commercial software vendors of the following products have claimed that the current versions of their products are Y2K compliant:

Obviously, older versions of these major vendors' products may be susceptible to Y2K difficulties. The vendors' representations were for their current versions only. For the Y2K compliance of other genealogy software not listed above, contact your vendor directly for information.

What should you do?

There are a series of steps family historians can take now to determine whether or not they face a problem with the year 2000.

First, if your genealogy software vendor is not on the list above as being Y2K compliant, contact your vendor and ask what you need to do to avoid any problems. If you are not using the most current version of the genealogy software programs on the above list, you will want to upgrade to avoid any problems.

Determine from your PC manufacturer whether your make and model of personal computer will handle the roll over to the year 2000. This would involve contacting them directly and may involve determining what BIOS version you are running.

If you are unable to determine from the manufacturer of your PC or BIOS as to their Y2K compliance, you may need to test your PCs ability to handle the date change yourself as follows. (Note that the test dates given below are for the change to the new year. The date February 28th, 2000 may be substituted for December 31st, 1999 below and February 29th, 2000 for January 1st, 2000 below to test for leap year compliance.)

  1. BACK UP EVERYTHING of value to you on your PC. This is a critical first step in doing any type of testing.

  2. Then try to set your PC's clock past the year 2000 to 1 a.m., January 1st, 2000. If the date is shown correctly, power off your PC, power it back on and recheck the date.

  3. If your PC passed the test of manually resetting the time, go on to testing its ability to automatically roll over to the correct date. Set your PC's clock to 23:58 p.m., December 31st, 1999. Keep the power on and watch for the next two minutes to determine if the date rolls correctly. If it is correct, power the PC off and back on again and recheck the date.

  4. Finally, check the PC's ability to automatically roll over to the correct date when not in use. Set your PC's clock to 23:58 p.m., December 31st, 1999 and power the PC off. Wait over 2 minutes and power the PC back on and check the date.

If your PC does not pass any of these tests and you are unable to obtain assistance from your PC's manufacture, then 1999 may be your year to invest in a new PC.


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Got a Date for the Millennium? - What Genealogists should know about the Year 2000
Created & maintained by Mark Howells.
For information about this article, please send email to markhow@oz.net
Updated February 17, 1999

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