A century, a century, an age is a period of time equal to one hundred years. According to the modern chronology (from the "Christmas of Christ"), a century begins with the "first" year, and ends with a multiple of a hundred. For example, the twentieth century began on January 1, 1901, and ended on December 31, 2000.
Names of centuries
Centuries are named by numbers according to the system, starting with the first, which lasted from 1 to 100 years. Zero century does not exist. We live in the 21st century, which began in 2001. That is, our century will end on December 31, 2100.
Written notation of centuries
In writing, centuries are usually denoted by Roman numerals, although Arabic numerals are also possible.
In all European countries and most countries of the world, the modern chronology of our era, including the 21st century and the 3rd millennium, is based on the Nativity of Christ and is denoted in Latin > Anno Domini, or abbreviated: A.D./AD. The complete phrase sounds: lat. Anno Domini Nostri Iesu Christi (in the year of our Lord Jesus Christ). According to this chronology, there is no zero year, therefore 1 year AD (new era) comes immediately after 1 year before Christmas (before the new era). In the Ukrainian language, the equivalent "year of God", "year of God" (b. B.) is used.
Anno Domini (Since Christmas)