Egyptian Calendar

1
Egyptian Calendar

• Jemma An
• Brian Kim
• Sung Jun Park

2
Preface

• Life Before the Discovery
• Egyptian calendar???
• Social Impact
• Problem
• Solution Improvement
• New Insight!!

3
Life Before the Discovery

• Farming was the most important industry in
  Ancient Egypt during BC 4200.
• Ancient Egypt had been suffered through flood,
  which occurred during similar period of the Nile
  River for a long time.
• So knowing the sowing and the harvesting period
  before flood of Nile was extremely important.
• Before people discovered Egyptian calendar,
  people marked the star Sirius before sunrise,
  and when next time they see the star Sirius,
  they considered as it passed one year.

4
Egyptian Calendar???

• Consisted of 360 days a year.
• Consisted of three seasons, each made up of 4
  seasons, and each month contains 30 days.
• Corresponded with the cycles of the Nile
• Inundation (June 21st to October 21st)
• Emergence (October 21st to February 21st)
• Summer (February 21st to June 21st)

5
Egyptian Calendar???

• Although the calendar consisted of 360 days, they
  actually had 365 day.
• They had the yearly five days at the beginning
  of the year.
• The yearly five days are times of great feasting
  and celebration for the Egyptians.

6
Social Impact

• The Egyptian calendar had an importance well
  beyond its purely Egyptian use.
• Old Egyptian calendar is used by lots of
  astronomers through out ancient and Middle Ages.
  The reasons lots of astronomers used were,
  Egyptian calendar had absolute regularity in the
  number of days in both months and the year. Those
  facts made astronomers to calculate much easier.

7
Social Impact

• Such regularity was extremely desirable, as
  ancient had neither Arabic numerals nor even
  concept of zero to make complex mathematics
  tractable.
• The Egyptian calendar can still be easily found
  in Egypt these days. Especially by the fellahin
  who rely on Egyptian calendar to calculate the
  agricultural seasons.
• It is also related with many of local festivals
  through out the country.

8
Problems

• The actual solar year is almost 365. 25 days.
• So the Egyptian calendar system is off by ¼ days
  a year.
• As the calendar uses continues the days of the
  season went off massively.
• For example, if it has been used for 100 years
  then they will end up with 24 more days a year.

9
Solution Improvement!

• Julius Caesar adopted the Egyptian calendar in
  Rome and tried to correct this problem.
• As a result, every 4 year he added additional 1
  day. (366 days)
• Added as 29th of February.
• But still, with this changes, there were still
  errors with the true solar year as time goes by.
  
• Every 100 years there were 0.78 days of error.

10
Solutions Improvement!

• Since Easter is occurring at the wrong time Pope
  Gregorian developed a new calendar based on the
  Roman Calendar.
• With the Gregorian Calendar it has an error of
  0.0003 days per year.
• This is the calendar which we use!!!

11
New Insight!

• Egyptian Calendar was the first calendar that
  appeared in the world.
• Used Nile River and stars to measure the year and
  completed the calendar.
• Whenever the Nile River overflows, Sirius star
  appeared.
• Used 36 stars and divided through out the year so
  it became 10 days week cycle, which means 36
  weeks in a year.
• Still used in some countries Egypt, Ethiopia,
  and so on.

12
Thank You!! ?

• http//www.polysyllabic.com/calhistory/earlier/egy
  ptian
• http//en.wikipedia.org/wiki/Egyptian_calendar
• http//kin.naver.com/db/detail.php?d1id11dir_id
  110107eidGu16dmnRyCuqdi/qptV8eqPmjLyl5PPhqbwMz
  B/caut8I
• http//www.mnsu.edu/emuseum/prehistory/egypt/daily
  life/calendar.html