Amazing secrets are found in calendars widely used around the world. This calendar era is based on the year of the birth of Jesus. The time period was divided into B.C. (Before Christ) and A.D. (Anno Domini) which is a Latin expression that means 'in the year of the Lord.' So, A.D. refers to the time period after Christ's birth. The calendar era demonstrates that the birth of Jesus is a real, historical fact.

This dating system was devised in 525 by Dionysius Exiguus of Scythia Minor who prepared a table of the future dates of Easter. It gained popularity during the reign of Charlemagne in the 9th century and has been widely used still today.