Using Timelinesto UnderstandHistory
The Gregorian Calendar
•Invented by the Romans.
•Improved by Pope Gregory XIII –he added Leap Year.
•Events are relative the date thatChristians believed Jesus wasborn.
Other Calendars
It is currently the year:
•2014 on the Christian calendar
•5775 on the Hebrew calendar
•1435 AH on the Islamic calendar
•Year of the Horse on the Chinesecalendar
The Gregorian Calendar
•BC = “Before Christ”
•AD = “Anno Domini”
– No, it does not mean “after death”.
– Latin meaning: “the year of ourlord”.
– This year is 2014 years sinceChristians believe Jesus was born.
The New System
•BCE means “Before the CommonEra”
44 BCE = 44 BC
•CE means “Common Era”
2014 CE = 2014 AD
Similar to Number Lines
0
-2
-1
1
2
1 CE
2 BCE
1 BCE
2 CE
3 CE
Relative Time
•YA = “years ago”
•Dinosaurs died out 65 million YA
•Earliest humans: 4 million YA
Rough Estimates of Dates
•Ca. = circa = “around the timeof”
•Remember: circa sounds like“circle” which is round.
•First stone tools were made ca. 2million years ago.
http://nationalgeographic.com