AD and BC

Sometimes you see Years written like

2000 AD

550 BC

What does it mean?

	AD is AFTER Jesus was born
	BC is BEFORE Jesus was born

AD comes from Latin Anno Domini meaning "In the year of Our Lord"

BC comes from Before Christ

Years Before and After

So, 550 BC means 550 years before Jesus was born

And 2000 AD almost means 2000 years after Jesus was born ...

... except ... AD started at 1, not 0

So, 2 AD is actually 1 Year after Jesus was born
And 2000 AD is actually 1999 Years after Jesus was born.

Except we don't really know WHEN Jesus was born!

Some historians put the actual birth of Jesus 4 years earlier (4 BC), but it WAS thought to be exactly at 1 AD.

A monk named Dionysius Exiguus calculated that his present year was 525 AD

And if you number all the years from then you get our current year number.

So, AD is now just a "Year Number" (every New Year we add 1), and it only roughly equals how many years ago that Jesus Christ was born.

"2000 AD" or "AD 2000"

Should "AD" be written before or after the number?

It WAS common to write it before (the standard was to put "AD" before the year and "BC" after), but now many people put "AD" after the year number. So you decide!

Other Calendars

There are other ways of saying what year it is!

Example, Muslims have dates that relate to Mohammad's emigration from Mecca to Medina called the Hijra, and so they use AH dates. The Year 2008 AD is 1429 AH (but the years don't have an exact match, because AH years are shorter!)