Anno Domini Year System and Centuries
In the Anno Domini (AD) year system used in the Gregorian calendar, there is no year zero.
In this system, the year 1 BC comes immediately after the year 1 AD.
Counting years in the Gregorian calendar starts in the year A.D.1 without a year zero.
The first hundred years ran from AD 1 until the end of AD 100.
Significant Years and Events
Movies released in 1999 included Fight Club, Being John Malkovich, American Beauty, The Blair Witch Project, and The Sixth Sense.
1999 is not as frequently discussed in pop-culture and philosophy as "The Matrix."
The 21st Century and Common Era
The twenty-first century in the Anno Domini era began in the year MMI (2001) and will end in MMC (2100).
2021 is considered part of the twenty-first century in the Gregorian calendar.