TAMU Computing and Information Services

 

Year 2000 Team: Why is the Year 2000 a problem?

 

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Year 2000 is just the year after 1999. This progression of years is rather natural to us. Unfortunately this progression of years does not exist in many computer applications. For years, well meaning programmers have been storing years in the two digit format of YY. As the years progress these computer systems see the years as 97, 98, 99, 00, 01 ... At first glance the use of two digit years doesn't seem to cause us any reason for alarm. We know that 00 should be 2000 and that it follows 1999. However computer applications that use two digits for year storage will not know the century. The years 1900, 2000, and 2100 will be stored as 00. When a computer application sorts by year then the year 00 will be before 99, therefore treating the year 00 as if it was 1900. Computer applications will also compute date calculations incorrectly when using two digit years. To illustrate this problem here is how computers may calculate an age in the year 2000, for someone who was born in 1945:

 

2000 - 1945 = 55

00 - 45 =-45 in a signed 2 digit integer field

00 - 45 = 45 in an unsigned 2 digit integer field

 

As you can see from the example, this person's age in the year 2000 may be calculated to be 45 instead of 55. If you were born before 1950 you'll be able to say that you are younger than you really are!

 

Just imagine how inventory items with an expiration date of 00 or beyond will be handled by automatic inventory systems. Will the inventory system in the 90's flag the new item as old and automatically create an order for a another item? That could be very expensive.

 

Another problem with the year 00 is that an application may reject the year. That may really sound goofy, but many systems have been written so that if the year is zero then prompt for the year again.

 

You may have heard that this is a mainframe problem only. That's not true! This problem exists in any computer system, computer application, or computerized hardware that uses two digits for the year. I wonder if the security system to our building will let me in on January 1, 2000.

 

You may also be thinking that you don't have to worry about this problem, yet. Wrong! If you do any kind of date projections with your computer systems, such as, calculate expected date of graduation. Then you will have year 2000 problems before the year 2000 is here.

You may also be thinking that you'll just buy the year 2000 compliant version of your software. Then you should contact your vendor and ask them if their software is year 2000 compliant. Hopefully they have plans underway to be year 2000 compliant.

 

Do you receive data from other sources outside of your area? Does this information contain dates? Do you know how they are planning on implementing changes for the year 2000? Will their changes effect your system?

 

Don't wait. Find out how your systems process dates.

 

Kim Reverman

CIS Year 2000 Team Leader

Computing and Information Services

Texas A&M University

 

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Last Modified: Wednesday, 06-Nov-96 00:18:39 CST

 

Texas A & M University

Computing & Information Services

Teague Building, Room 228

College Station, Texas, U.S.A. 77843

Kim-Reverman@tamu.edu