Calendar Definition

There is several definition for calendar. Oxford Dictionary explain several definition for calendar. Those are;
1. Calendar is a chart showing the days, weeks and months of a particular year
2. A device that can be adjusted to show the date each day
3. A list of dates or events of a particular type
4. A system by wich time is divided into fixed periods, showing the begining and end of a year.
In the other hand, Micosoft Encarta Dictionaries also explain several devinition for a calendar. Those are;
1. Calendar is a chart of year.
The chart showing the days and months of the year, espesially a particular year.
2. System of calculating year
It means that calendar is a system of calculating the days and months of the year and when the year begins an ends.
3. Calendar is Schedule
Calendar is a schedule of events, usually covering a period of a year.
4. Calendar is List
Calendar also define as an official list of things to be done or considered.
By those definition we can conclude that common calendar definition is a system of measuring time that divided into days, weeks, months and year.

Calendar system

Calendar is a system by wich time is divided into fixed period, showing the begining and end of a year (Oxford Dictionary). Usually a calendar represent by chart showing days, weeks and months of a particular year. Day is a term for the average time required for one rotation of the earth. In other word, a day is a time from the morning time to the next morning time.
There is two major system to measuring year. The first system is the solar calendar. The solar calendar using the earth revolution cycling the sun as the refference. It means that one year at the solar calendar is the time takes by the earth to complete cycling the sun. A year, in Solar calendar contains approximately 365,25 days.
The second calendar system is the lunar calendar. The lunar calendar using the moon revolution cycling the earth as the refference.  It means that one year at the lunar calendar is the time takes by the moon to complete cycling the earth. A year in Lunar Calendar contains 354 days.
Both lunar and solar calendar are used to measuring and remembering days for several purpose. The difference is that the solar calendar is more popular than the lunar calendar.  But that doesn’t mean that the lunar calendar is no more used. The lunar calendar used by several religion to calculate the time of their holidays. Hindu, Islam, and Jew are using the moon revolution period as a refference for their calendar system .