Year 2000

Year 2000 (MM) was a leap year starting on Saturday (link will display full 2000 Gregorian calendar). It is generally pronounced as "two thousand"; however, in keeping the tradition of previous centuries (e.g. 1900s, 1800s) could also be referred to as "twenty hundred" since, mathematically speaking, 2000=20×100. In the Chinese Calendar, it is the Year of the Dragon, and in the western astrological calendar, it is the year of Leo, the Lion. Popular culture also holds the year 2000 as the first year of the twenty first century and the third millennium. In the Gregorian Calendar, however, this distinction falls to the year 2001. This is because the first century began with the year 1 (there was no year zero), the first century (or first 100 years AD) was from January 1, in the year one (AD 1) through December 31, in the year one-hundred (AD 100). The second century began on January 1, in the year one-hundred and one (101 AD). (The selection of AD 1 may be up to seven years from Jesus' birth, and January 1 is a historical choice for New Year's Day.). The same reasoning applies to millenniums, where the first ends on the year one-thousand (1000 AD).
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<programming> (Y2K, or "millennium bug") A common name for all the difficulties the turn of the century, or dates in general, bring to computer users.
Back in the 1970s and 1980s, the turn of the century looked so remote and memory/disk was so expensive that most programs stored only the last two digits of the year. These produce surprising results when dealing with dates after 1999. They may believe that 1 January 2000 is before 31 December 1999 (00time shifting.
And yes, the year 2000 was a leap year (multiples of 100 aren't leap years unless they're also multiples of 400).
PPR Corp Y2K FAQ.
(2003-08-15)

As we approach the end of this millennium, many users of data analysis software have discovered that their programs do not support dates with a year designation that starts with any other digits but "19." Thus, effectively, that software is incompatible with the dates that will soon become a reality (and even now need to be used in modeling, forecasting, etc.). STATISTICA (see University site licenses) is one of very few programs that is not only "year-2000 compatible" but, also so-called, "year-2000-friendly" by offering flexible options to customize the operation of the program (e.g., the interpretation of ambiguous date designations, such as 1/1/20, where 20 could mean 1920 or 2020), to meet different specific needs of the data analysts.