Year 2000 (Y2K) Problem

Date: 07/26/98 at 16:46:39
From: Janis Rose - The Internet Studio
Subject: Y2K

Can you explain the Year 2000 problem in layman's terms? I keep
hearing about code that has to be rewritten and how it's just not 
possible in the time left. I don't understand why it just can't be 
rewritten.

Thanks,
Jan

Date: 07/30/98 at 21:48:42
From: Doctor Jeremiah
Subject: Re: Y2K
Hi Jan.

This is a very good question.

The short answer is "It can be rewritten" but of course then you 
realize it will take more than two years. Here is why:

When you write down a year like 12/23/34 you really mean 12/23/1934.

Notice the two extra digits. For the last 40 years all the dates stored 
in computers have been missing those two digits. Now that the year 2000 
is coming, we have two problems:

1) The data in the computers will be wrong. Say you were born
   on 12/23/34. After the year 2000 the computers will probably
   think that means 2034 when it really means 1934. So all the
   data have to be fixed.

2) All the software that people use for entering the data and doing
   calculations on the data tries to use dates with two-digit years.
   Once all the data are fixed we can't continue to pretend dates
   have two-digit years. So all the software has to be fixed.

There are a lot of data and people have been making software that uses 
two-digit years for 40 years. These two things put together will take a 
very long time to fix.

The problem is that we only have two years left. If we had fifteen then 
we would be okay. If we had 5 times as many computer professionals we 
would perhaps be able to do it in two years. But there just isn't 
enough time or enough people.

Pretend that it is 12/31/99 and the computers think that means
12/31/1999. Now, when the date changes to 01/01/00 the computers will
think that this means 01/01/1900.

Say your bank is giving you 3 perent interest annually and you have 
$1000 in the bank. The interest is 8.1 cents per day. But going from
12/31/1999 to 01/01/1900 is -100 years (-36500 days instead on just 
+1 day). If they added the interest for this many days they would have 
to subtract $2956 from your account and then mail you a letter saying 
that you owed them $1956.

So you can see that it is a big problem. It can't be fixed fast enough
and the consequences are really difficult.

I hope that helps answer your question. Write back if you have other 
questions.

- Doctor Jeremiah, The Math Forum
Check out our web site! http://mathforum.org/dr.math/