World Civ
August 16, 2012
The Dating of Time
Have you ever given much
thought to time?
How important are dates and time
to your daily life?
 If
you were asked the
question: “What year
were you born,” each of
you would automatically
respond with a number
(1996 or 1997). But have
you actually thought
about what this number
means???
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In our system of dating, events
are dated by counting backward
or forward from the birth of
Christ (the year “1”).
Events that occurred before the
birth of Christ are labeled “BC”
Events that occurred after the
birth of Christ are labeled “AD”
anno domini – “in the year of our
Lord”
 Some historians/books use BCE
and CE instead.

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The year of my birth is AD 1982.
This means I was born 1,982
years after the birth of Christ.
An event that happened 400
years before the birth of Christ
would be dated 400 B.C.
Terms: decade=10 years
century= 100 years
millenium= 1,000 years
Understanding Centuries
100 BC – 1 BC = 1st century BC
200 BC – 101 BC = 2nd cent BC
300 BC – 201 BC = 3rd cent BC
400 BC – 301 BC = 4th cent BC
Etc…
1 – 100 = 1st century
101 – 200 = 2nd century
201 – 300 = 3rd century
…
1801 – 1900 = 19th century
1901 – 2000 = 20th century
2001 – 2100 = 21st century
Why do you need to know this
anyway?
http://isotropic.org//date/
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We use the Gregorian Calendar
(after Pope Gregory XIII) (1582)
But not all people use this
calendar system. What other
calendar systems are used?
What’s the difference between
the Julian and Gregorian
calendars?
For Future Reference
Exit Slip Activity
Complete the following
questions:
1.) What century were you born
in?
2.) Queen Elizabeth I died in
1603. Which century is this?
3.) Thomas Edison invented the
light bulb in the 19th century.
What years?

Exit Ticket
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4.) Why did the Gregorian
calendar replace the Julian
calendar?
5.) How would you correctly
write King Henry the 8th using
Roman Numerals?
6.) Louis XIV is what number?