Hi all
The Topic is What is "YEAR 2038 BUG"?
Answer of this question is following

A> That Is Me (My Id)

B> It is similar to Y2k problem.It will occur just a second after
Tue 19 jan 03:14:07 2038.This will effect the system which use POSIX time system(Time system used in UNIX).

WHY POSIX: It actually represent the time and date in number of seconds since 1 january 1970.so the problem is it uses 32 bit signed integer (that the max capablity which 32 bit microprocessor can handle) for repesentation of time and date.The max combination can occur is 2 to the power 31 which is equal to 2147483647. SO this means that at tue 19 jan 03:14:07 2038 it will reperesent it as 2147483647 and just a second after it,it will be -2147483648 which changes date to Fri 13 Dec 20:45:52 1901. So some also call it as 13th friday bug.

Here a programme which I found in a site for this problem
Code:
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <time.h>

int main (int argc, char **argv)
{
    time_t t;
    t = (time_t) 1000000000;
    printf ("%d, %s", (int) t, asctime (gmtime (&t)));
    t = (time_t) (0x7FFFFFFF);
    printf ("%d, %s", (int) t, asctime (gmtime (&t)));
    t++;
    printf ("%d, %s", (int) t, asctime (gmtime (&t)));
    return 0;
}
output
Code:
1000000000, Sun Sep  9 01:46:40 2001
2147483647, Tue Jan 19 03:14:07 2038
-2147483648, Fri Dec 13 20:45:52 1901
and my personal experincewhich i have encountered this problem is
Code:
1> Change your date to just a second after the critical time
2> Now Run Some Applicatins Like I have Tried yahoo messenger
3> Look what happned.It will not work.

Note : I have tried this thing on Win98.
for more information visit;-}
http://www.2038bug.com/index.html -from where i get code
http://en.wikipedia.org/wiki/2038_bug -online encyclopedia
http://www.johntitor.com/ -The man from future