Understanding the AD and BC Time Labeling System

AD stands for 'Anno Domini,' Latin for 'in the year of the Lord,' referring to the birth of Jesus Christ. BC denotes 'Before Christ.' These terms are used to label or number years in the Julian and Gregorian calendars.

The AD/BC system was devised by Dionysius Exiguus in the 6th century to enumerate the years in his Easter table. His system was to replace the Diocletian era that was used in an old Easter table.

In the AD/BC system, there is no year zero. The calendar goes from 1 BC to AD 1 directly. This absence is due to the number zero not being introduced to Europe until the Middle Ages.

Years before AD 1 are labeled as BC, which moves in descending order. For instance, 200 BC comes before 100 BC. This is reverse to the ascending order of years in the AD system.

Today, 'Common Era' (CE) and 'Before Common Era' (BCE) are often used instead of AD and BC. The terms are favored for their religious neutrality, important in our globally connected and diverse world.

The exact year of Jesus’s birth is debated by scholars, which means the AD/BC division might not accurately reflect history. Some suggest Jesus was born between 6 and 4 BC.

While many cultures maintain their own calendar systems, the AD/BC system is globally recognized for international trade, science, and historical scholarship, demonstrating its significant influence.