Calender
(s.k. hussain)
The calendar today
Most people in the Western World use the Gregorian calendar, worked out in the 1580''s by Pope Gregory XIII. It has 12 months, 11 of them with 30 or 31 days. The other month, February, normally has 28 days. Every fourth year, called a leap year, it has 29 days. But even this calendar is not quite exact enough. In century years that cannot be divided by 400, such as 1700, 1800, and 1900, the extra day in February must be dropped. The century year 1600 was a leap year, and the year 2000 will be one.
In 1972, the leap second was introduced into calendar keeping. In 1958, the second was given a new atomic definition. However, this new definition produced a different number of total seconds in a year from year to year, due to irregularities in the earth''s rotation rate. Thus, it is occasionally necessary to add or subtract a leap second to keep the time shown on clocks in step with time based on astronomical observations.
Our calendar is supposed to be based on the year Jesus Christ was born. Dates before that year are listed as B.C., or before Christ. Dates after that year are listed as A.D., or anno Domini (in the year of our Lord). Non-Christians often write B.C.E., for before Christian era, and C.E., for Christian era. See B.C.; A.D.; CHRISTIAN ERA.Write your abstract here.
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