03-17-2023-1755 - The start of the 21st century and 3rd millennium was celebrated worldwide at the start of the year 2000. (wikipedia)

The start of the 21st century and 3rd millennium was celebrated worldwide at the start of the year 2000. One year later, at the start of the year 2001, the celebrations had largely returned to the usual ringing in of just another new year,^[7] although some welcomed "the real millennium", including America's official timekeeper, the U.S. Naval Observatory,^[8] and the countries of Cuba^[9] and Japan.^[10] 

https://en.wikipedia.org/wiki/Millennium