1. CALENDAR SYSTEM Presented By S.SATHISH

2. CONTENT  INTRODUCTION  TYPES OF CALENDAR  SOLAR CALENDARS  JULIAN CALENDAR  LUNAR CALENDARS  LUNISOLAR CALENDARS  CONCLUSION

3. INTRODUCTION  The calendar is a system of arranging the year into days, weeks and months.  The purpose of the calendar is to reckon past or future time, to show how many days until a certain event takes place: -Harvest -Religious festival -How long since something important happened  No one knows who invented the first calendar.  No one knows when the first calendar was invented.

4. TYPES OF CALENDARS  SOLAR CALENDARS  LUNAR CALENDARS  LUNISOLAR CALENDARS

5. SOLAR CALENDARS  Solar Calendar is finalized on the basis of movement of the Earth around the Sun.  One revolution of the earth around the sun equals one year, or 365.242199 days.  It has 365 days in a year but every fourth year is a leap year i.e. an extra day is added to the month of February.  Julian Calendar, Gregorian calendar, Malayalam calendar and Thai calendar are some of the examples of solar calendar.

6. JULIAN CALENDAR  It is introduced by Julius Caesar, was first used in 45 BC.  The calendar had 365 days in a year comprising of 12 months.  Every fourth year was celebrated as a leap year with a day added to February.  Julius Caesar’s calendar started with the month of March and ended with the month of February.

7. JULIAN CALENDAR HISTORY  Julius Cesar was a famous Roman Emperor.  He wanted a new calendar for his empire.  He picked the Egyptian calendar and changed it a little bit.  Julius Caesar expanded the Roman empire until it covered parts of Africa, Asia and Europe.  As the empire grew, the calendar went with it. That is why European countries use this calendar.

8. NAME OF THE MONTHS Julius Caesar named the months of the year as follow  March- the Roman god Mars  April- the old Roman calendar month of Aprilis  May- the Roman goddess Maia  June- the Roman goddess Juno  July- named after Julius Caesar  August- named for the Roman emperor Augustus  September- from the Latin septem which means seven  October- from the Latin octo or eight

9.  November- from the Latin nove or nine  December- from the Latin decem or ten  January- the Roman god Janus  February- the Roman purification festival Februa

10. LUNAR CALENDARS  It is based on Movement of the moon around the earth.  One revolution of the moon around the earth equals one month.  It has 12 lunation or months comprising of 29 to 30 days as against 30 to 31 days in a Solar Calendar.  In some lunar calendars like Chinese calendar, a month starts on the day of the arrival of the new moon while in others, the first day of the month is determined by the day the crescent of the moon is sighted.  Islamic calendar, Hindu calendar and Chinese calendar are some of the examples of lunar calendars.

11. The moon’s movement around the earth

12. ISLAMIC CALENDAR  It is generally used in all Muslim-dominated countries, always consists of 12 lunation or months in a year of 354 or 355 days.  Mainly used for religious purposes, this calendar helps Muslims all over the world determine Islamic holy days like Id, Moharram etc.

13. LUNISOLAR CALENDARS  The Luni-solar calendar is based on the movement of the moon around the earth and the earth around the sun.  A lunisolar calendar is a lunar calendar that compensates by adding an extra month as needed to realign the months with the seasons.  An example is the Hebrew calendar which uses a 19-year cycle.

14. HEBREW CALENDAR  The Hebrew calendar is used for religious purposes by Jews all over the world, and it is one of the official calendars of Israel  A Hebrew calendar day does not begin at midnight, but at either sunset or when three medium-sized stars should be visible, depending on the religious circumstance.

15. CONCLUSION Inspire of that fact that we all know the system of that calendar that we use now, we should realize that it is the great creation of people and also our ancestors spend thousands of years to create calendar.