The Year 2000 problem was a problem for both digital (computer-related) and non-digital documentation and data storage situations which resulted from the practice of abbreviating a four-digit year to two digits.
In 1997, the British Standards Institution (BSI) developed a standard, DISC PD2000-1, which defines a "2000 compliance" as the four rules:
No actual date will not cause any interruption in operations.
The calculation of the duration between them, or sequence, a pair of dates will be whether any dates in a different century.
In all interfaces and all storage, the century must be unambiguous, or given or calculated by an algorithm
2000 should be recognized as a leap year
It distinguishes two problems which may exist in a variety of computer programs.
First, the practice of representing the year with two digits becomes problematic with logical error (s) arising in "rollover" from x99 to x00. This caused some date-related processing to a malfunction of the dates and time from January 1, 2000 and on other critical dates which were declared "event horizon." Without corrective action, long-working systems would break down when the "...97, 98, 99, 00..." ascending numbering assumption suddenly became invalid.
Second, some programmers have misunderstood the rule that determines whether the years that are exactly divisible by 100 are leap years, and took over in 2000 is not a leap year. Although most years divisible by 100 are not leap years, unless they are divisible by 400, then they are. Thus, 2000 was a leap year.
Companies and organizations around the world to check, fixed and upgraded their computer systems.
The number of computer glitches that occurred when the clocks rolled over into 2000, despite the repair work is not known, among other reasons, is the reluctance of organizations to report problems.